temperature

[tem-per-uh-cher, -choor, -pruh-, -per-cher]

noun

1. a measure of the warmth or coldness of an object or substance with reference to some standard value. The temperature of two systems is the same when the systems are in thermal equilibrium. T

2. Physiology, Pathology.

   1. the degree of heat in a living body, normally about 98.6°F (37°C) in humans.

   2. the excess of this above the normal.

3. Obsolete.,  mildness, as of the weather.

4. Obsolete.,  temperament.

temperature

/ ˈtɛmprɪtʃə /

noun

1. the degree of hotness of a body, substance, or medium; a physical property related to the average kinetic energy of the atoms or molecules of a substance

2. a measure of this degree of hotness, indicated on a scale that has one or more fixed reference points

3. informal,  a body temperature in excess of the normal

4. archaic

   1. compromise

   2. temperament

   3. temperance

temperature

1. A measure of the ability of a substance, or more generally of any physical system, to transfer heat energy to another physical system. The temperature of a substance is closely related to the average kinetic energy of its molecules.

2. See also Boyle's law

3. Any of various standardized numerical measures of this ability, such as the Kelvin, Fahrenheit, and Celsius scales.

4. An abnormally high body temperature; a fever.

Usage

Heat and temperature are closely related but distinct and sometimes subtle ideas. Heat is simply transferred thermal energy—most commonly, the kinetic energy of molecules making up substance, vibrating and bouncing against each other. A substance's temperature, on the other hand, is a measure of its ability to transfer heat, rather than the amount of heat transferred. For example, a match lit under a pot of boiling water reaches a much higher temperature than the water, but it is able to give off much less heat, since only a small amount of thermal energy is created and released by it. When any two substances of different temperatures are in thermal contact, the laws of thermodynamics state that heat flows from the higher-temperature substance into the lower-temperature substance, raising the temperature of the heated body and lowering the temperature of the body releasing heat until thermal equilibrium is reached, and the temperatures are the same. Thus temperature describes a characteristic of matter that determines the direction and extent of heat transfer, so the match with little heat but high temperature still adds energy to the water when placed under the pot. Providing a closed physical system with heat generally raises its temperature but not necessarily; for example, ice at zero degrees Celsius requires considerable additional heat in order to melt into water at zero degrees Celsius. Temperature can be related to the average kinetic energy of the molecules of gases, though this relation breaks down in most real cases involving liquids, solids, substances with larger molecules, and radiation with no mass, such as light. The two most common temperature scales, Celsius (C) and Fahrenheit (F), are based on the freezing and boiling points of water. On the Celsius scale there are 100 increments between the two points, and on the Fahrenheit scale there are 180. Scientists also use the International System units called Kelvins (K). A difference in temperature of one degree is equivalent in the Celsius and Kelvin scales, but their absolute scales are different: while zero degrees C is the temperature at which water freezes (at a pressure of one atmosphere), zero degrees K (−273.72 degrees C), also called absolute zero, is the least possible temperature for a system, representing a theoretical state from which no heat can be extracted.

Word History and Origins

Origin of temperature¹

First recorded in 1525–35, temperature is from the Latin word temperātūra a tempering. See temperate, -ure

Word History and Origins

Origin of temperature¹

C16 (originally: a mingling): from Latin temperātūra proportion, from temperāre to _temper

Idioms and Phrases

see run a fever (temperature).

Example Sentences

His approach, involving coils filled with cold water, turned out to be a great way to lower ambient air temperatures, too.

Read more on The Wall Street Journal

Tests showed that the W-DEG continued to function under a wide range of temperatures and salt levels, and even when exposed to natural lake water containing biofouling.

Read more on Science Daily

It takes place 10 years after the Paris climate agreement, in which countries pledged to try to restrict the rise in global temperatures to 1.5C.

Read more on BBC

Maximum daytime temperatures on Monday are expected drop by as much as 8 degrees Celsius in England and Wales compared with Thursday.

Read more on BBC

Before bringing me water, they even asked my temperature preference.

Read more on The Wall Street Journal

Related Words

• climate 
• cold 
• condition 
• heat 
• warmth