Copyright © Philip M. Parker, INSEAD. Terms of Use.
Definition: Cool |
CoolAdjective1. Neither warm or very cold; giving relief from heat; "a cool autumn day"; "a cool room"; "cool summer dresses"; "cool drinks"; "a cool breeze". 2. Marked by calm self-control (especially in trying circumstances); unemotional; "play it cool"; "keep cool"; "stayed coolheaded in the crisis"; "the most nerveless winner in the history of the tournament". 3. (color) inducing the impression of coolness; used especially of greens and blues and violets; "cool greens and blues and violets". 4. Psychologically cool and unenthusiastic; unfriendly or unresponsive or showing dislike; "relations were cool and polite"; "a cool reception"; "cool to the idea of higher taxes". 5. (informal; of a number or sum) without exaggeration or qualification; "a cool million bucks". 6. (informal) fashionable and attractive at the time; often skilled or socially adept; "he's a cool dude"; "that's cool"; "Mary's dress is really cool"; "it's not cool to arrive at a party too early". Noun1. The quality of being cool: "the cool of early morning". 2. Great coolness and composure under strain; "keep your cool". Verb1. Make cool or cooler; "Chill the food". 2. Loose heat; The air cooled considerably after the thunderstorm". 3. Lose intensity; "His enthusiasm cooled considerably". Source: WordNet 1.7.1 Copyright © 2001 by Princeton University. All rights reserved. |
Date "cool" was first used in popular English literature: sometime before 1010. (references) |
| Domain | Definition |
Computing | CooL |
Mechanical Engineering | To extract sensible or latent heat; usually taken as to lower temperature. Source: European Union. (references) |
Multilingual Slang | Austrian (geil , leiwand), Hungarian (húzós, Tök jó), Spanish (chaci, dabuten, guay), Vietnamese (xi.n). (references) |
Slang | Phungky. (references) |
Source: compiled by the editor from various references; see credits. | |
(From Wikipedia, the free Encyclopedia)
Cool is a city located in Parker County, Texas. As of the 2000 census, the city had a total population of 162.Geography
Cool is located at 32°47'54" North, 98°0'46" West (32.798472, -98.012781)1. According to the United States Census Bureau, the city has a total area of 4.2 km² (1.6 mi²). 4.2 km² (1.6 mi²) of it is land and none of the area is covered with water.Demographics
As of the census of 2000, there are 162 people, 62 households, and 49 families residing in the city. The population density is 38.1/km² (98.9/mi²). There are 69 housing units at an average density of 16.2/km² (42.1/mi²). The racial makeup of the city is 96.91% White, 0.00% African American, 0.00% Native American, 0.00% Asian, 0.00% Pacific Islander, 2.47% from other races, and 0.62% from two or more races. 3.70% of the population are Hispanic or Latino of any race. There are 62 households out of which 32.3% have children under the age of 18 living with them, 64.5% are married couples living together, 11.3% have a female householder with no husband present, and 19.4% are non-families. 17.7% of all households are made up of individuals and 8.1% have someone living alone who is 65 years of age or older. The average household size is 2.61 and the average family size is 2.92. In the city the population is spread out with 24.7% under the age of 18, 4.3% from 18 to 24, 27.8% from 25 to 44, 22.8% from 45 to 64, and 20.4% who are 65 years of age or older. The median age is 41 years. For every 100 females there are 90.6 males. For every 100 females age 18 and over, there are 96.8 males. The median income for a household in the city is $30,938, and the median income for a family is $31,875. Males have a median income of $36,875 versus $22,917 for females. The per capita income for the city is $14,112. 20.9% of the population and 16.4% of families are below the poverty line. Out of the total people living in poverty, 26.7% are under the age of 18 and 15.2% are 65 or older.Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Cool, Texas."
(From Wikipedia, the free Encyclopedia)
In physics, the relationship between heat and energy is similar to that between work and energy. Heat is said to flow from areas of high temperature to areas of low temperature. All objects have a certain amount of energy within them that is related to the random motion of their atoms. This internal energy is directly proportional to the temperature of the object. When two bodies of different temperature come in to thermal contact, they will exchange internal energy until the temperature is equalized. The amount of energy transferred is the amount of heat exchanged. It is a common misconception to confuse heat with internal energy, but there is a difference, and understanding the difference is a necessary part of understanding the first law of thermodynamics.
Changes of Temperature
The amount of heat energy, , required to change the temperature of a material from an initial temperature, T0, to a final temperature, Tf depends on the heat capacity of that material according to the relationship:
The heat capacity is dependent on both the amount of material that is exchanging heat and its properties. The heat capacity can be broken up in several different ways. First of all, it can be represented as a product of mass and specific heat capacity (more commonly called specific heat):
or the number of moless and the molar heat capacity:
- Cp = m cs
Both the molar and specific heat capacities only depend upon the physical properties of the substance being heated, not on any specific properties of the sample. The above definitions of heat capacity only work approximately for solids and liquids, but for gases they don't work at all most of the time. The molar heat capacity can be "patched up" if the changes of temperature occur at either a constant volume or constant pressure. Otherwise, it's generally easiest to use the first law of thermodynamics in combination with an equation relating the internal energy of the gas to its temperature.
- Cp = n cmolar
Changes of State
A boiling pot of water, at sea level and normal atmospheric pressure, will always be at 100oC no matter how much heat is added. The extra heat changes the state of the water from liquid into water vapor. The heat added to change the state of a substance in this way is said to be "hidden," and thus it is called latent heat (from a Latin word for hidden). Latent heat is the rate of heat per unit mass necessary to change the state of a given substance. Thus:
and:
- dQ/dm = L (should this be a partial derivative or a full one?)
where Mo is the amount of mass initially in the new phase, and M is the amount of mass that ends up in the new phase.
L generally doesn't depend on the amount of mass that changes phase, so the equation can normally be written:
Sometimes L can be time-dependent if pressure and volume are time-varying, so that the integral can be handled:
- Q = L Δm
someone check the above, please, to see if the latent heat really depends on where on the (P, V, T) curve the transition is taking place.
- Q = ∫L (dm/dt) dt
How Heat Moves
As mentioned previously, heat tends to move from a high temperature region to a low temperature region. This heat transfer may occur by any of three mechanisms, conduction, convection, and radiation.
Conduction is the most common means of heat transfer in a solid. On a microscopic scale, conduction occurs as hot, rapidly moving or vibrating atoms and molecules interact with neighboring atoms and molecules, transferring some of their energy (heat) to these neighboring atoms.
Convection is usually the dominant form of heat transfer in liquids and gases. In convection, heat transfer occurs by the movement of hot or cold portions of the fluid. For example, when water is heated on a stove, hot water from the bottom of the pan rises, heating the water at the top of the pan. Two types of convection are commonly distinguished, free convection, in which gravity and buoyancy forces drive the fluid movement, and forced convection, where a fan, stirrer, or other means is used to move the fluid.
Radiation is the final means of heat transfer. Radiative heat transfer is the only form of heat transfer that can occur in the absence of any form of medium and as such is the only means of heat transfer through a vacuum. Thermal radiation is a direct result of the movements of atoms and molecules in a material. Since these atoms and molecules are composed of charged particles (protons and electrons), their movements result in the emission of electromagnetic radiation, which carries energy away from the surface. At the same time, the surface is constantly bombarded by radiation from the surroundings, resulting in the transfer of energy to the surface. Since the amount of emitted radiation increases with increasing temperature, a net transfer of energy from higher temperatures to lower temperatures results.
Other Important Heat Transfer Mechanisms
Latent Heat
Transfer of heat through a physical change in the medium such as water/ice or water/steam involves significant energy and is exploited in many ways steam engine, refrigerator etc.
Heat Pipe
A heat transfer mechanism using latent heat and capilliary action to move heat. A heat pipe can carry many times as much heat as a similar sized copper rod and is starting to have applications in laptop personal computers.
See also
- Heat pump
- Shock heating
- Heat death of the Universe
- Heat, the movie
Heat is a popular term for estrus, a period of increased sexual drive in female mammals.
Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Heat."
(From Wikipedia, the free Encyclopedia)
In physics, temperature is the physical property of a system which underlies the common notions of "hot" and "cold"; generally the material with the higher temperature is said to be hotter.
Formally, temperature is that property which governs the transfer of thermal energy, or heat, between one system and another. When two systems are at the same temperature, they are in thermal equilibrium and no heat transfer will occur. When a temperature difference does exist, heat will tend to move from the higher temperature system to the lower temperature system, until thermal equilibrium is again established. This heat transfer may occur via conduction, convection or radiation (see heat for additional discussion of the various mechanisms of heat transfer). The formal properties of temperature are studied in thermodynamics. Temperature also plays an important role in almost all fields of science, including physics, chemistry, and biology.
Temperature is related to the amount of thermal energy or heat in a system. As more heat is added the temperature rises, similarly a decrease in temperature corresponds to a loss of heat from the system. On the microscopic scale this heat corresponds to the random motion of atoms and molecules in the system. Thus, an increase in temperature corresponds in an increase in the rate of movement of the atoms in the system.
Many physical properties of materials including the phase (gas, liquid or solid), density, solubility, vapor pressure, and electrical conductivity depend on the temperature. Temperature also plays an important role in determining the rate and extent to which chemical reactions occur. This is one reason why the human body has several elaborate mechanisms for maintaining the temperature at 37 °C, since temperatures only a few degrees higher can result in harmful reactions with serious consequences. Temperature also controls the type and quantity of thermal radiation emitted from a surface. One application of this effect is the incandescent light bulb, in which a tungsten filament is electrically heated to a temperature at which significant quantities of visible light are emitted.
Temperature is an intrinsic property of a system, meaning that it does not depend on the system size or the amount of material in the system. Other intrinsic properties include pressure and density. By contrast, mass and volume are extrinsic properties, and depend on the amount of material in the system.
Units of Temperature
The basic unit of temperature in the International System of Units is the kelvin (K). One kelvin is formally defined as 1/273.16 of the temperature of the triple point of water (the point at which water, ice and water vapor exist in equilibrium). The temperature 0 K is called absolute zero and corresponds to the point at which the molecules and atoms have the least possible thermal energy. No macroscopic system can have a temperature less than absolute zero. An important unit of temperature in theoretical physics is the Planck temperature (1.4×1032 K).
For everyday applications, it is often convenient to use the Celsius (previously centigrade) scale, in which 0 °C corresponds to the temperature at which water freezes and 100 °C corresponds to the boiling point of water at sea level. In this scale a temperature difference of 1 degree is the same as a 1 K temperature difference, so the scale is essentially the same as the kelvin scale, but offset by the temperature at which water freezes (273.15 K). Thus the following equation can be used to convert from Celsius to kelvin.
In the United States, the Fahrenheit scale is widely used. On this scale the freezing point of water corresponds to 32 °F and the boiling point to 212 °F. The following formula can be used to convert between Fahrenheit and Celsius:
Other temperature scales include the Rankine and the Reaumur.
Theoretical foundation of temperature
Zeroth-Law definition of temperature
While most people have a basic understanding of the concept of temperature, its formal definition is rather complicated. Before jumping to a formal definition, let's consider the concept of thermal equilibrium. If two closed systems with fixed volumes are brought together, so that they are in thermal contact, changes may take place in the properties of both systems. These changes are due to the transfer of heat between the systems. When a state is reached in which no further changes occur, the systems are in thermal equilibrium.
Now a basis for the definition of temperature can be obtained from the 'zeroth law of Thermodynamics, which states that if two systems, A and B, are in thermal equilibrium and a third system C is in thermal equilibrium with system A then systems B and C will also be in thermal equilibrium. This is an empirical fact, based on observation rather than theory. Since A, B, and C are all in thermal equilibrium, it is reasonable to say each of these systems shares a common value of some property. We call this property temperature.
Generally, it is not convenient to place any two arbitrary systems in thermal contact to see if they are in thermal equilibrium and thus have the same temperature. Therefore, it is useful to establish a temperature scale based on the properties of some reference system. Then, a measuring device can be calibrated based on the properties of the reference system and used to measure the temperature of other systems. One such reference system is a fixed quantity of gas. Boyle's law indicates that the product of the Pressure and volume (P×V) of a gas is directly proportional to the temperature. This can be expressed by the Ideal gas law as:
where T is temperature, n is the amount of gas (number of moless) and R is the Ideal gas constant. Thus, one can define a scale for temperature based on the corresponding pressure and volume of the gas. In practice, such a gas thermometer is not very convenient, but other measuring instruments can be calibrated to this scale.
- (1)
Equation 1 indicates that for a fixed volume of gas, the pressure increases with increasing temperature. Pressure is just a measure of the force applied by the gas on the walls of the container and is related to the energy of the system. Thus, we can see that an increase in temperature corresponds to an increase in the thermal energy of the system. When two systems of differing temperature are placed in thermal contact, the temperature of the hotter system decreases, indicating that heat is leaving that system, while the cooler system is gaining heat and increasing in temperature. Thus heat always moves from a region of high temperature to a region of lower temperature and it is the temperature difference that drives the heat transfer between the two systems.
Second-Law definition of temperature
In the previous section temperature was defined in terms of the Zeroth Law of thermodynamics. It is also possible to define temperature in terms of the second law of thermodynamics, which deals with entropy. Entropy is a measure of the disorder in a system. The second law states that any process will result in either no change or a net increase in the entropy of the universe. This can be understood in terms of probability. Consider a series of coin tosses. A perfectly ordered system would be one in which every coin toss would come up either heads or tails. For any number of coin tosses, there is only one combination of outcomes corresponding to this situation. On the other hand, there are multiple combinations that can result in disordered or mixed systems, where some fraction are heads and the rest tails. As the number of coin tosses increases, the number of combinations corresponding to imperfectly ordered systems increases. For a very large number of coin tosses, the number of combinations corresponding to ~50% heads and ~50% tails dominates and obtaining an outcome significantly different than 50/50 becomes extremely unlikely. Thus the system naturally progresses to a state of maximum disorder or entropy.
Now, we have stated previously that temperature controls the flow of heat between two systems and we have just shown that the universe, and we would expect any natural system, tends to progress so as to maximize entropy. Thus, we would expect there to be some relationship between temperature and entropy. In order to find this relationship let's first consider the relationship between heat, work and temperature. A Heat engine is a device for converting heat into mechanical work and analysis of the Carnot heat engine provides the necessary relationships we seek. The work from a heat engine corresponds to the difference between the heat put into the system at the high temperature, qH and the heat ejected at the low temperature, qC. The efficiency is the work divided by the heat put into the system or:
where wcy is the work done per cycle. We see that the efficiency depends only on qC/qH. Because qC and qH correspond to heat transfer at the temperatures TC and TH, respectively, qC/qH should be some function of these temperatures:
- (2)
Carnot's theorem states that all reversible engines operating between the same heat reservoirs are equally efficient. Thus, a heat engine operating between T1 and T3 must have the same efficiency as one consisting of two cycles, one between T1 and T2, and the second between T2 and T3. This can only be the case if:
- (3)
which implies:
Since the first function is independent of T2, this temperature must cancel on the right side, meaning f(T1,T3) is of the form g(T1)/g(T3) (i.e. f(T1,T3) = f(T1,T2)f(T2,T3) = g(T1)/g(T2)×g(T2)/g(T3) = g(T1)/g(T3)), where g is a function of a single temperature. We can now choose a temperature scale with the property that:
Substituting Equation 4 back into Equation 2 gives a relationship for the efficiency in terms of temperature:
- (4)
Notice that for TC=0 K the efficiency is 100% and that efficiency becomes greater than 100% below 0 K. Since an efficiency greater than 100% violates the first law of thermodynamics, this implies that 0 K is the minimum possible temperature. In fact the lowest temperature ever obtained in a macroscopic system was 20 nK, which was achieved in 1995 at NIST. Subtracting the right hand side of Equation 5 from the middle portion and rearranging gives:
- (5)
where the negative sign indicates heat ejected from the system. This relationship suggests the existence of a state function, S, defined by:
where the subscript indicates a reversible process. The change of this state function around any cycle is zero, as is necessary for any state function. This function corresponds to the entropy of the system, which we described previously. We can rearranging Equation 6 to get a new definition for temperature in terms of entropy and heat:
- (6)
For a system, where entropy S may be a function S(E) of its energy E, the termperature T is given by:
- (7)
The reciprocal of the temperature is the rate of increase of entropy with energy.
- (8)
Heat capacity
Also see Specific heat capacity.
Temperature is related to the amount of thermal energy or heat in a system. As heat is added to the system, the temperature increases by an amount proportional to the amount of heat being added. The constant of proportionality is called the heat capacity and reflects the ability of the material to store heat.
The heat is stored in a variety of modes, corresponding to the various quantum states accessible to the system. As the temperature increases more quantum states become accessible, resulting in an increase in heat capacity. For a monatomic gas at low temperatures, the only accessible modes correspond to the translational motion of the atoms, so all of the energy is due to movement of the atoms (Actually, a small amount of energy, called the Zero Point Energy arises due to the confinement of the gas into a fixed volume, this energy is present even at 0 K). Since the kinetic energy is related to the motion of the atoms, 0 K corresponds to the point at which all atoms are motionless. For such a system, a temperature below 0 K is not possible, since it is not possible for the atoms to move slower than to be motionless.
At higher temperatures, electronic transitions become accessible, further increasing the heat capacity. For most materials these transitions are not important below 104 K, however for a few common molecules, such transitions are important even at room temperature. At extremely high temperatures (>108 K) nuclear transitions become accessible. In addition to translational, electronic, and nuclear modes, polyatomic molecules also have modes associated with rotation and vibrations along the molecular bonds, which are accessible even at low temperatures. In solids most of the stored heat corresponds to atomic vibrations.
Negative Temperatures
At low temperatures, particles tend to move to their lowest energy states. As you increase the temperature, particles move into higher and higher energy states. As the temperature becomes infinite, the number of particles in the lower energy states and the higher energy states becomes equal. In some situations, it is possible to create a system in which there are more particles in the higher energy states than in the lower ones. This situation can be described with a negative temperature. A negative temperature is not colder than absolute zero, but rather it is hotter than infinite temperature.The previous section described how heat is stored in the various translational, vibrational, rotational, electronic, and nuclear modes of a system. The macroscopic temperature of a system is related to the total heat stored in all of these modes and in a normal system thermal energy is constantly being exchanged between the various modes. However, for some cases it is possible to isolate one or more of the modes. In practice the isolated modes still exchange energy with the other modes, but the time scale of this exchange is much slower than for the exchanges within the isolated mode. One example is the case of nuclear spins in a strong external magnetic field. In this case energy flows fairly rapidly among the spin states of interacting atoms, but energy transfer between the nuclear spins and other modes is relatively slow. Since the energy flow is predominantly within the spin system, it makes sense to think of a spin temperature that is distinct from the temperature due to other modes.
Based on Equation 7, we can say a positive temperature corresponds to the condition where entropy increases as thermal energy is added to the system. This is the normal condition in the macroscopic world and is always the case for the translational, vibrational, rotational, and non-spin related electronic and nuclear modes. The reason for this is that there are an infinite number of these types of modes and adding more heat to the system increases the number of modes that are energetically accessible, and thus the entropy. However, for the case of electronic and nuclear spin systems there are only a finite number of modes available (often just 2, corresponding to spin up and spin down). In the absence of a magnetic field, these spin states are degenerate, meaning that they correspond to the same energy. When an external magnetic field is applied, the energy levels are split, since those spin states that are aligned with the magnetic field will have a different energy than those that are anti-parallel to it.
In the absence of a magnetic field, one would expect such a two-spin system to have roughly half the atoms in the spin-up state and half in the spin-down state, since this maximizes entropy. Upon application of a magnetic field, some of the atoms will tend to align so as to minimize the energy of the system, thus slightly more atoms should be in the lower-energy state (for the purposes of this example we'll assume the spin-down state is the lower-energy state). It is possible to add energy to the spin system using radio frequency (RF) techniques. This causes atoms to flip from spin-down to spin-up. Since we started with over half the atoms in the spin-down state, initially this drives the system towards a 50/50 mixture, so the entropy is increasing, corresponding to a positive temperature. However, at some point more than half of the spins are in the spin-up position. In this case adding additional energy, reduces the entropy since it moves the system further from a 50/50 mixture. This reduction in entropy with the addition of energy corresponds to a negative temperature. For additional information see [1].
Temperature in gases
As mentioned previously for a monatomic ideal gas the temperature is related to the translational motion or average speed of the atoms. The Kinetic theory of gases uses Statistical mechanics to relate this motion to the average kinetic energy of atoms and molecules in the system. For this case 11300 degrees Celsius corresponds to an average kinetic energy of one electronvolt; to take room temperature (300 kelvin) as an example, the average energy of air molecules is 300/11300 eV, or 0.0273 electronvolts. This average energy is independent of particle mass, which seems counterintuitive to many people. Although the temperature is related to the average kinetic energy of the particles in a gas, each particle has its own energy which may or may not correspond to the average. In a gas the distribution of energy (and thus speeds) of the particles corresponds to the Boltzmann distribution.
An electronvolt is a very small unit of energy, on the order of 1.602e-19 joules.
Temperature Measurement
Many methods have been developed for measuring temperature. Most of these rely on measuring some physical property of a working material that varies with temperature. One of the most common devices for measuring temperature is the glass thermometer. This consists of a glass tube filled with mercury or some other liquid, which acts as the working fluid. Temperature increases cause the fluid to expand, so the temperature can be determined by measuring the volume of the fluid. Such thermometers are usually calibrated, so that one can read the temperature, simply by observing the level of the fluid in the thermometer. Another type of thermometer that is not really used much in practice, but is important from a theoretical standpoint is the gas thermometer mentioned previously.
Other important devices for measuring temperature include:
One must be careful when measuring temperature to ensure that the measuring instrument (thermometer, thermocouple, etc) is really the same temperature as the material that is being measured. Under some conditions heat from the measuring instrument can cause a temperature gradient, so the measured temperature is different from the actual temperature of the system. In such a case the measured temperature will vary not only with the temperature of the system, but also with the heat transfer properties of the system. An extreme case of this effect gives rise to the wind chill factor, where the weather feels colder under windy conditions than calm conditions even though the temperature is the same. What is happening is that the wind increases the rate of heat transfer from the body, resulting in a larger reduction in body temperature for the same ambient temperature.
- Thermocouples
- Thermistors
- Resistance Temperature Detector (RTD)
- Pyrometers
- Other thermometers
See also: color temperature, Timeline of temperature and pressure measurement technology
Articles about temperature ranges:
- 1 picokelvin
- 1 nanokelvin
- 1 microkelvin
- 1 millikelvin
- 1 kelvin
- 10 kelvin
- 100 kelvin
- 1,000 kelvin
- 10,000 kelvin
- 100,000 kelvin
- 106 kelvin
- 109 kelvin
- 1012 kelvin
- 1015 kelvin
- 1018 kelvin
- 1021 kelvin
- 1024 kelvin
- 1027 kelvin
- 1030 kelvin
External links
- An elementary introduction to temperature aimed at a middle school audience
- National Science Digital Library - Temperature
- How to Convert Temperatures : A middle school lesson plan on converting temperatures.
Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Temperature."
| The following table is compiled from various sources, across various languages. When English abbreviations or acronyms come from a non-English source, this is noted. | |||
| Entry | Source | Expression | Field |
COOL | English | Common Object Oriented Library project | Finance |
Source: compiled by the editor, based on several corpora (additional references). | |||
Synonyms: CoolSynonyms: coolheaded (adj), nerveless (adj), aplomb (n), assuredness (n), poise (n), sang-froid (n), self-possession (n), chill (v), cool down (v), cool off (v). (additional references) |
| Antonyms: warm (adj), heat (v). (additional references) |
| Context | Synonyms within Context (source: adapted from Roget's Thesaurus). |
Caution | Unenterprising, unadventurous, cool, steady, self-possessed; overcautious. |
Cold | Adjective: cold, cool; chill, chilly; icy; gelid, frigid, algid; fresh, keen, bleak, raw, inclement, bitter, biting, niveous, cutting, nipping, piercing, pinching; clay-cold; starved. (made cold); chilled to the bone, shivering. Verb: aguish, transi de froid; frostbitten, frost-bound, frost-nipped. |
Discourtesy | Uncivil, ungracious, unceremonious; cool; pert, forward, obtrusive, impudent, rude, saucy, precocious. |
Dissuasion | Disincline, indispose, shake, stagger; dispirit; discourage, dishearten; deter; repress, hold back, keep back; (restrain); render averse; repel; turn aside; (deviation); wean from; act as a drag; (hinder); throw cold water on, damp, cool, chill, blunt, calm, quiet, quench; deprecate. |
Enmity | On bad terms, not on speaking terms; cool; cold, cold hearted; estranged, alienated, disaffected, irreconcilable. |
Indifference | Adjective: indifferent, cold, frigid, lukewarm; cool, cool as a cucumber; unconcerned, insouciant, phlegmatic, pococurante, easygoing, devil-may-care, careless, listless, lackadaisical; half-hearted; unambitious, unaspiring, undesirous, unsolicitous, unattracted. |
Moderation | Tranquilize, pacify, assuage, appease, swag, lull, soothe, compose, still, calm, calm down, cool, quiet, hush, quell, sober, pacify, tame, damp, lay, allay, rebate, slacken, smooth, alleviate, rock to sleep, deaden, smooth, throw cold water on, throw a wet blanket over, turn off; slake; curb; (restrain); tame; (subjugate); smooth over; pour oil on the waves, pour oil on the troubled waters; pour balm into, mattre de l'eau dans son vin. |
Adjective: moderate; lenient; gentle, mild, mellow; cool, sober, temperate, reasonable, measured; tempered; Verb: calm, unruffled, quiet, tranquil, still; slow, smooth, untroubled; tame; peaceful, peaceable; pacific, halcyon. | |
| Source: adapted from Roget's Thesaurus. | |
Crosswords: Cool |
| English words defined with "cool": cool down, cool it, cool off ♦ To cool the heels. (references) |
| Specialty definitions using "cool": Cool Card, COOL CRAPE, Cool Hundred, COOL LADY, COOL NANTS, COOL TANKARD ♦ Keep your Breath to Cool your Porridge. (references) |
| Etymologies containing "cool": Kele. (references) |
| Non-English Usage: "Cool" is also a word in the following language with English translations in parentheses. German (cool, fair, laid back, safe, smooth, together). |
| Domain | Usage | |
Screenplays | It was kinda cool. (American Beauty; writing credit: Alan Ball) It's cool, Troy, you can stay (Reality Bites; writing credit: Ben Stiller, written by Helen Childress.) Because they make you feel cool, and hey, I met you. You are not cool (Almost Famous; writing credit: Cameron Crowe) As long as you're asking, why not go for a cool million (Coming to America; writing credit: David Sheffield) You're so cool and fine and always so much your own. There's a kind of beautiful purity about you, Tracy, like, like a statue (The Philadelphia Story; writing credit: Donald Ogden Stewart) | |
Lyrics | She was a long cool woman in a black dress (Long Cool Woman (In a Black Dress); performing artist: Hollies) Sailing on the cool and bright clear waters (Cool Change; performing artist: Little River Band) Just cool it down and stay in control (Cool It Now; performing artist: New Edition) You've gotta be cool on Wall Street (Wall Street Shuffle; performing artist: 10CC) But if you wanna get down, baby, it's cool (I Do (Wanna Get Close To You); performing artist: 3LW) | |
Clever | Being cool is not trying to be cool. (references; author: unknown) It is important to stay cool, but be sure to not get frostbite. (references; author: unknown) To cool a hot attitude, apply nice. To melt a cold attitude, address warmly. (references; author: unknown) 1968: Moving to California because it's cool. 1998: Moving to California because it's warm. (references; author: unknown) As a rule, man's a fool. When it's hot, he wants it cool. And when it's cool, he wants it hot; always wanting what is not. (references; author: unknown) | |
Movie/TV Titles | Cool Million (1972) Cozy Cool (1971) Cool It Carol! (1970) Charlie Cool It (1969) Medium Cool (1969) | |
Song Titles | Long Cool Woman (performing artist: Hollies) Cool Water (performing artist: Jack Scott) Cool Change (performing artist: Little River Band) Cool It Now (performing artist: New Edition) Cool Love (performing artist: Pablo Cruise) | |
Source: compiled by the editor from various references; see credits. | ||
| Domain | Title | ||
Books | |||
Periodicals |
| ||
Theater & Movies | |||
Music |
| ||
High Tech |
| ||
Consumer Goods |
| ||
Source: compiled by the editor from various references; see credits. | |||
| Thumbnail | Description & Credit | Thumbnail | Description & Credit |
 | Smoking might look cool in the movies, but in real life it stinks!. Credit: CDC. |  | "Cool" (movie) by Jimmy Forsman. |
 | Columns of cool interstellar hydrogen gas and dust in M16, the Eagle Nebula. Credit: NASA. |  | Fishing at the Florida Power warm water discharge site on a cool Florida day. Credit: Fisheries. |
 | Volunteers plant naturally occurring vegetation at the stream bed. When the vegetation is mature it will help to cool the stream and provide favorable conditions for spawning. Credit: NOAA Restoration Center. |  | A student plants small native shrubs and trees in the riparian corridor to keep the stream cool. Credit: NOAA Restoration Center. |
 | Deck hand Mike Theberge and two scientific observers cool off in a jungle stream on Isla Cocos. Credit: Small World. |  | Switchgrass pasture in Union County, Iowa. Native grasses including switchgrass offer pasture for cattle in mid-summer when cool season pastures such as bluegrass are less productive. Credit: Lynn Betts. |
 | Large fans keep hogs in ferring house cool. Credit: Bob Nichols. |  | Hog wallowing to keep cool. Credit: USDA. |
Source: pictures compiled by the editor from various references; see picture credits. | |||
 |  |
| "Cool Nikko" by Nikko the Shiba Inu Commentary: "Nikko, my two year old Shiba Inu looking cool in his new shades." | "Cool Metal Pirates" by Jaime Krayger Commentary: "Sculpture outside historic Key West fort." |
Source: photographs selected by the editor, with permission from the photographers. | |
| Play | Caption | Play | Caption |
 | Harmon-muted trumpet melody in a cool, easy swing style using modern harmonies. | | Air conditioner being turned on and motorized fan begins to blow cool air. |
| Source: compiled by the editor from various references; see credits. | |||
| Author | Quotation |
Daniel Webster | Keep cool; anger is not an argument. |
George Washington | It is only after time has been given for cool and deliberate reflection that the real voice of the people can be known. |
President Woodrow Wilson | One cool judgment is worth a thousand hasty counsels. The thing to be supplied is light, not heat. |
Quentin Crisp | Manners are love in a cool climate. |
Rupert Brooke | The cool kindliness of sheets, that soon smooth away trouble; and the rough male kiss of blankets. |
Sir Walter Scott | But with morning cool repentance came. |
St. Just | Keep cool and you command everybody. |
Thomas Jefferson | Nothing gives a person so much advantage over another as to remain always cool and unruffled under all circumstances. |
William Mcfee | The world belongs to the enthusiast who keeps cool. |
Source: compiled by the editor from various references. | |
| Title | Author | Quote |
Sea Dirge | Carroll, Lewis | I try the rocks, and I think it cool That they laugh with such an excess of glee, As I heavily slip into every pool That skirts the cold cold Sea. |
Scarlet Letter | Hawthorne, Nathaniel | Its cool stare of familiarity was intolerable |
Les Miserables | Hugo, Victor | He had a certain cool and quiet laugh, which was particularly dangerous |
Portrait of the Artist as a Young Man | Joyce, James | Very cool and mollifying |
Grapes of Wrath | Steinbeck, John | When it gets cool, take the rack outa the oven |
Walden | Thoreau, Henry David | This is as important as that it keeps butter cool. |
Source: compiled by the editor from various references. | ||
| Subject | Topic | Quote |
Health | Drink cool liquids between meals. (references) | |
Try softer, cool, or frozen foods, such as yogurt, milkshakes, or popsicles. (references) | ||
Sleeping in a cool room may keep hot flashes from waking you up during the night. (references) | ||
Business | Singaporeans are generally concerned about keeping cool in the nation’s tropical climate. (references) | |
Of this, 40% goes towards air-conditioning to cool buildings all year round and a further 25% in refrigeration. (references) | ||
Unlike the U.S. or European countries with seasonal climates, Singapore relies heavily on air-conditioning to cool its buildings all year round. (references) | ||
Economic History | Andorra | Climate: Temperate, cool, dry. (references) |
Cyprus | Climate: Mediterranean with hot, dry summers and cool, wet winters. (references) | |
Laos | The relationship remained cool until 1982 when efforts at improvement began. (references) | |
Political Economy | Burma | Official relations between the United States and Burma have been cool since the 1988 military coup and violent suppression of pro-democracy demonstrations. (references) |
Travel | Mexico | Above this is the cool region, including Mexico City, at 7,300 feet. (references) |
New Zealand | A sweater should be carried even during the summer months, as the evenings can become cool. (references) | |
Source: compiled by the editor from ICON Group International, Inc.; see credits. | ||
| Speaker | Phrase(s) |
Joan Lunden | I love that. It was so cool. But I jumped out of a plane with the Golden Knights. They're the best experts in the world. |
Joan Rivers | In school. I watch my diet all the time. Truly, truly, I watch my diet, but I cheat. I live on Cool Whip. I am an all inside plastic person. |
Mariah Carey | People ask me that a lot. I wouldn't want to do Broadway where I had to sing the same way every night. But something funny, some type of comedic thing would be cool, like an off Broadway thing. |
Mattie Stepanek | That was very exciting. It is a wonderful foreword, and that was just really, really cool when we heard that Maya Angelou was indeed doing the foreword. |
Rush Limbaugh | So when Jimmy Carter called and said that Kim Il Sung was a cool guy, Clinton jumped at the chance to pass more impotent UN resolutions or sign another meaningless piece of paper. |
Source: compiled by the editor from various references; see credits. | |
| "Cool" is generally used as an adjective (general or positive) -- approximately 71.59% of the time. "Cool" is used about 2,556 times out of a sample of 100 million words spoken or written in English. Its rank is based on over 700,000 words used in the English language. Some parts-of-speech are not covered due to the samples used by the British National Corpus. (note: percents less than one-hundredth of one percent have been omitted) |
| Parts of Speech | Percent | Usage per 100 Million Words | Rank in English |
| Adjective (general or positive) | 71.59% | 1,830 | 4,638 |
| Lexical Verb (infinitive) | 17.62% | 451 | 12,908 |
| Lexical Verb (base form) | 6.45% | 165 | 24,305 |
| Adverb (general) | 2.93% | 75 | 38,535 |
| Noun (singular) | 0.98% | 25 | 69,787 |
| Noun (proper) | 0.43% | 11 | 106,044 |
| Total | 100.00% | 2,556 | N/A |
Source: compiled by the editor from several corpora; see credits.
| The following table summarizes the usage of "cool" based on a population census conducted in the United States. Ranks and frequencies are based on all names reported and classified. |
| Name | Usage/Gender | Usage per 100 million Persons | Rank in USA |
| Cool | Last name | 2,000 | 6,327 |
| Source: compiled by the editor from several corpora; see credits. | |||
| The following table summarizes names derived from the word "cool". | |||
| Name | Gender | Language | Meaning |
| Colbert | Male | English | To be cool and bright |
| Source: compiled by the editor from various references.
| |||
1. Cool, CA 2. Cool, TX (city, FIPS 16540) |
Expressions using "cool": as cool as a cucumber ♦ as cool as cucumber ♦ as cool as you please ♦ become cool ♦ catch cool ♦ cool air ♦ cool as a cucumber ♦ cool as a custard ♦ cool as custard ♦ cool bag ♦ cool blooded ♦ cool cat ♦ cool down ♦ cool drink ♦ cool it ♦ cool it! ♦ cool jazz ♦ cool off ♦ cool ones heels ♦ cool one's heels ♦ cool reception ♦ cool Ridge ♦ cool Valley ♦ feel cool ♦ get cool ♦ grow cool ♦ he is a cool hand ♦ it is cool ♦ keep cool ♦ keep in a cool place ♦ keep one's breath to cool one's porridge ♦ keep one's cool ♦ loose one's cool ♦ Mc Cool ♦ Mc Cool Junction ♦ nice and cool ♦ play cool ♦ play it cool ♦ To cool the heels ♦ what cool cheek! ♦ with a cool head. Additional references. | |
| Hyphenated Usage | |
Beginning with "cool": cool-as-ice, cool-bag, cool-box, cool-coloured, cool-eyed, cool-funk, Cool-headed, Cool-headedness, cool-kitsch, cool-light, cool-looking, cool-man, cool-mannered, cool-thinking, cool-warm. | |
Ending with "cool": ice-cool. | |
| Source: compiled by the editor from various references; see credits. | |
| The following statistics estimate the number of searches per day across the major English-language search engines as identified by various trade publications. Hyperlinks lead to commercial use of the expression at Amazon.com. |
| Expression | Frequency per Day | Expression | Frequency per Day |
ll cool j | 4,268 | cool t shirt | 390 |
cool | 2,787 | cool quiz | 390 |
cool edit | 2,008 | cool hair style | 382 |
cool picture | 1,411 | cool tattoo | 371 |
cool car | 1,328 | cool job | 370 |
cool edit pro | 1,193 | aint it cool | 365 |
cool wallpaper | 1,091 | cool house plan | 362 |
cool quote | 1,084 | cool name screen | 353 |
cool background | 998 | ll cool j picture | 352 |
cool stuff | 988 | cool doll | 352 |
cool web site | 975 | cool name | 346 |
cool clothes | 973 | cool runnings | 345 |
cool game | 817 | cool whip | 332 |
cool web page | 741 | cool icon | 308 |
aint it cool news | 707 | cool edit 2000 | 286 |
cool site | 645 | cool links | 273 |
ain cool it news t | 581 | cool hand luke | 271 |
cool font | 522 | cool teen chat | 270 |
cool msn name | 510 | cool device | 245 |
cool buddy icon | 403 | cool screensaver | 241 |
| Source: compiled by the editor from various references; see credits. | |||
| Language | Translations for "cool"; alternative meanings/domain in parentheses. | |
Afrikaans | koel, bekoel (cool down). (various references) | |
Albanian | vetëpërmbajtje (composure, continence, control, forbearance, poise, restraint, self restraint, sobriety), rrumbullak (rotund, round, roundly), marr me qetësi, i qetë (at ease, balanced, calm, canny, collected, comfortable, comfy, composed, cool-headed, dispassionate, easeful, equable, even, even-minded, halcyon, laid back, level, level headed, mild, noiseless, orderly, Pacific, passionless, peaceable, peaceful, placid, quiescent, quiet, reposeful, retired, secure, sedate, self possessed, serene, settled, silent, smooth, sober-blooded, stationary, still, stilly, tranquil, unconcern, unconcerned, uneventful, unruffled), i lezetshëm (agreeable, comely, delicious, delightful, handsome, ingratiatingly, jolly, nice, pretty), i hijshëm (becoming, charming, comely, dainty, decent, decorous, delicate, delicious, distinguished, elegant, graceful, jimp, nice, personable), i ftohtë (algid, aloof, bleak, bloodless, brumous, chilly, cold, cold-livered, cool blooded, crimpy, distant, frigid, frosty, frozen, gelid, glacial, insensitive, offish, Parky, sexless, stilted, stolid, stony, winterly, wintry), i freskët (breezy, chilly, crisp, dewy, fresh, hot, new, new-laid, recent, sweet, unhackneyed, up to date), gjakftohtë (calm, cold blooded, dispassionate, even tempered, impassible, imperturbable, placid, self contained, self possessed, serene, sober-blooded, unflappable), ftoh (chill, gelation, grow cool, quench, refrigerate, switch off), freskoj (fresh, freshen, refresh, renovate, update), freski (coolness, freshness, youthfulness). (various references) | |
Arabic | فتر (cool down, flag, freeze, lag, languish), فاتر (apathetic, chilly, cold, disinterested, dispassionate, dull, frigid, half hearted, indifferent, languid, listless, lukewarm, slack, spiritless, stagnant, tepid, unenthusiastic, unfriendly), مكبوح الاهتياج, ممتاز (admirable, banner, best, bonny, boss, brave, choice, clipping, dandy, deluxe, distingue, distinguished, ducky, elegant, excellent, exceptional, exquisite, extra, famous, fancy, fine, first class, first rate, first-string, mighty, noble, of first degree, outstanding, premium, prime, select, splendid, star, stellar, super, superb, superior, swell, thoroughbred, thumbs up, tiptop, top notch, vintage, wizard), منعش (animating, bracing, cooling, exhilarating, fresh, invigorative, reanimating, recreating, recreative, refreshing, restorative, resuscitating, resuscitative, reviving, stimulating, stimulative), مشعر ببرودة, هادئ (calm, cloistered, composed, dispassionate, easygoing, even, impassive, imperturbable, laid back, peaceable, peaceful, piping, placid, possessed, quiescent, quiet, reposeful, restful, self possessed, serene, sober, steady, still, tranquil, undisturbed, uneventful, unflappable, unmoved, unruffled, windless), هدأ (allay, appease, assuage, attemper, becalm, calm, calm down, die down, dust, ease, hush, keep quiet, lull, moderate, mollify, pacify, palliate, placate, quench, quieten, relieve, rest, salve, settle, settle down, simmer, smooth, sober, soothe, stay, steady, still, subside, supple, sweeten, tranquillize), وقح (abrasive, barefaced, blatant, bold, brazen, flippant, hardy, impertinent, impudent, insolent, nervy, off hand, overbold, pert, presuming, presumptuous, rascal, rude, sassy, saucy, scamp, shameless, smart), سكن (alleviate, appease, assuage, attemper, calm, dwell, dwelling, dwelt, ease, fall, gentle, habitation, hostel, house, hut, kill, live, lodging, lull, occupy, pacify, palliate, place, qualify, quarters, quiet, quieten, remit, repose, residence, salve, set together, settle, solace, soothe, stay, still, supple, tenant), الصفيق, أصبح بارد, رابط الجأش (collected, composed, cucumber, imperturbable, nonchalant, philosophical, phlegmatical, possessed, self possessed), بارد (bleak, boring, chilly, cold, coldish, coolly, dank, distant, flat, glacial, meaningless, phlegmatic, phlegmatical, raw, silly, unfriendly, wintry), برودة بإعتدال (coolness). (various references) | |
Bulgarian | чудесен (admirable, beautiful, champion, clipping, corking, delicious, elegant, excellent, fabulous, famous, fine, glorious, gorgeous, great, heavenly, hot, immense, lovely, magnificent, marvellous, marvelous, neat, nifty, noble, priceless, rattling, regular, ripping, scrumptious, smashing, spanking, splendid, super, terrific, thundering, topping, walloping, wizard, wonderful), изтънчен (dainty, delicate, discriminating, fastidious, fine, polished, polite, refined, subtle, urbane), прохлада (coolness, fresh), без расистки прояви, безучастен (impersonal, indifferent, passive, unconcerned, unimpressed, vacant), лек (airy, bland, cure, cushy, easy, expedite, facile, fairy, flimsy, gentle, gossamer, gossamery, gradual, lambent, lenient, light, lightsome, lightweight, medicine, mild, mobile, potty, quiet, remedy, skyey, slick, slight, snap, soft, subtle, tenuous, unsound, unsubstantial), екстра (crack-a-jack, extra, first rate, gilt-edged, goluptious, nailing, primely, rattling, ripping, slick), забавям (arrest, defer, delay, detain, hang up, hold back, hold off, hold over, inhibit, postpone, put back, put over, retard, set back, sidetrack, slacken, slow, slow down, stave off, steady), надменен (airy, aloof, arrogant, assuming, assumptive, contemptuous, disdainful, haughty, high, high and mighty, imperious, lofty, offhand, offish, overbearing, overweening, prideful, proud, proud-stomached, remote, scornful, stand offish, stiff, stuck up, sublime, supercilious, superior, top-lofty, uppish), охладнявам (become cold, cool down), дързък (arrogant, assuming, audacious, cheeky, contumelious, daring, defiant, foolhardy, malapert, nervy, overbold, reckless, sassy, saucy, venturesome), цял (entire, full, good, intact, integral, integrate, livelong, overall, perfect, regular, right, round, sheer, solid, thorough, thoroughgoing, thorough-paced, total, unabridged, unbroken, undivided, whole), студен (algid, asepsis, bleak, bloodless, cold, dead, frigid, frosted |
