heat

American  

[heet] / hit /

noun

1. a relatively high degree of warmth.

   Antonyms:

   coolness

2. the condition or quality of being hot.

   The heat of the oven will caramelize the natural sugars in the vegetables, enhancing their flavor.

   Synonyms:

   warmth, hotness

3. the degree of hotness; temperature.

   Heat is measured with a thermometer.

   Moderate heat is sufficient for a child’s bathwater.

   Synonyms:

   caloricity

4. the sensation of warmth or hotness.

   She enjoyed the pleasant heat on her face and hands from the crackling fire.

5. a bodily temperature higher than normal.

   The heat caused by physical exertion is reduced by sweating.

6. added or external energy that causes a rise in temperature, expansion, evaporation, or other physical change.

   The application of heat causes particles of matter to move more rapidly.

7. Physics. a nonmechanical energy transfer with reference to a temperature difference between a system and its surroundings or between two parts of the same system. Q

8. a hot condition of the atmosphere or physical environment; hot season or weather.

   They go up north in the summer to escape the heat.

9. a period of hot weather.

10. a sharp, pungent flavor, as that produced by strong spices.

11. warmth or intensity of feeling; vehemence; passion.

    He spoke with much heat and at great length.

    Synonyms:

    impetuosity, excitement, fever, flush, zeal, fervor, ardor

    Antonyms:

    indifference

12. a point or period of high intensity in an action, process, situation, etc..

    Soldiers must make snap decisions in the heat of battle with no certainty of the outcome.

    In the heat of his hasty departure he forgot his keys.

13. Often the heat pressure to act, work, etc..

    All this media attention is putting the heat on him to change his position on the issue.

    Give me a deadline—I work best under a little heat.

14. Slang. intensified pressure verging on coercion and involving intimidation or implied threat, especially in a police investigation.

    They had to use heat to get the guy to give them some names.

15. Slang. the heat, the police.

    We split when we saw the heat coming.

16. Slang. armed protection, especially a pistol, revolver, or other firearm.

    All guards carry some heat.

17. a single intense effort; a sustained, concentrated, and continuous operation.

    The painting was finished at a heat.

18. Sports.

    1. a single course in or division of a race or other contest.

    2. a race or other contest in which competitors attempt to qualify for entry in the final race or contest.

19. Metallurgy.

    1. a single operation of heating, as of metal in a furnace, in the treating and melting of metals.

    2. a quantity of metal produced by such an operation.

20. Zoology.

    1. sexual receptiveness in animals, especially females.

    2. the period or duration of such receptiveness.

       Do not frequent dog parks or other dog-populated areas while your dog is in heat.

21. Slang. the heat, awesome or excellent; cool.

    Check out the photography on her website—that stuff’s the heat!

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verb (used with object)

heats, present (3rd person singular) heated, past participle, past heating present participle

1. to make hot or warm (often followed byup ).

   Let me heat this leftover soup in the microwave.

   Antonyms:

   cool

2. to excite emotionally; inflame or rouse with passion.

   Synonyms:

   animate, stir, warm, stimulate

verb (used without object)

heats, present (3rd person singular) heated, past participle, past heating present participle

1. to become hot or warm (often followed byup ).

   It takes a while for the house to heat up.

2. to become excited emotionally.

verb phrase

1. heat up to increase or become more active or intense.

   Business competition will heat up toward the end of the year.

heat British  

/ hiːt /

noun

1. 1. the energy transferred as a result of a difference in temperature

   2. the random kinetic energy of the atoms, molecules, or ions in a substance or body

2. the sensation caused in the body by heat energy; warmth

3. the state or quality of being hot

4. hot weather

   the heat of summer

5. intensity of feeling; passion

   the heat of rage

6. pressure

   the political heat on the government over the economy

7. the most intense or active part

   the heat of the battle

8. a period or condition of sexual excitement in female mammals that occurs at oestrus

9. sport

   1. a preliminary eliminating contest in a competition

   2. a single section of a contest

10. slang police activity after a crime

    the heat is off

11. slang criticism or abuse

    he took a lot of heat for that mistake

12. without pausing to think

13. 1. Also: in season.  (of some female mammals) sexually receptive

    2. in a state of sexual excitement

14. slang the police

15. informal to increase the intensity of activity, coercion, etc

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verb

1. to make or become hot or warm

2. to make or become excited or intense

heat Scientific  

/ hēt /

1. Internal energy that is transferred to a physical system from outside the system because of a difference in temperature and does not result in work done by the system on its surroundings. Absorption of energy by a system as heat takes the form of increased kinetic energy of its molecules, thus resulting in an increase in temperature of the system. Heat is transferred from one system to another in the direction of higher to lower temperature.

2. See also thermodynamics See Note at temperature

3. See estrus

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heat Cultural  

1. In physics, a form of energy associated with the movement of atoms and molecules in any material. The higher the temperature of a material, the faster the atoms are moving, and hence the greater the amount of energy present as heat. (See infrared radiation.)

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heat Idioms  

More idioms and phrases containing heat

• dead heat
• in heat
• in the heat of the moment
• turn up the heat

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Other Word Forms

Derived Forms

• reheat
  verb
• underheat
  verb (used with object)
• unheatable
  adjective
• heatlike
  adjective
• reheatable
  adjective
• self-heating
  adjective
• heatful
  adjective
• heatless
  adjective
• heatable
  adjective

Conjugated Forms

Present

• has heated
  perfect 3rd person singular
• have heated
  perfect
• am heating
  progressive 1st person singular
• have been heating
  perfect progressive
• is heating
  progressive 3rd person singular
• heats
  singular 3rd person
• heating
  participle
• are heating
  progressive
• has been heating
  perfect progressive 3rd person singular

Past

• had heated
  perfect
• had been heating
  perfect progressive
• was heating
  progressive singular
• heated
  simple
• were heating
  progressive plural
• heated
  participle

Future

• will heat
  simple
• will have heated
  perfect
• will be heating
  progressive
• will have been heating
  perfect progressive

Etymology

Origin of heat

First recorded before 900; Middle English hete, Old English hǣtu; akin to German Hitze; see hot

Explanation

Objects that give off heat — or a feeling of warmth — include the sun, a radiator, and even your body. You can feel a marked difference in air temperature if you hold your hand near the heat of a candle flame, for example. Heat can also mean the intensity of an emotion. In the heat of an argument, you need to watch what you say, because you may regret it later. The verb heat means to make something hot, like when you heat up last night's pizza to eat for lunch today. When things heat up, they become exciting or intense, the way thrilling chase scenes heat up your favorite action movie.

Example Sentences

Yet when heat is examined at distances far smaller than the width of a human hair, it can behave in unexpected ways.

From Science Daily • Jun. 8, 2026

There is a 20% chance that the weather service will issue heat advisories on Wednesday across the warmer valleys, in particular the southern Salinas, Santa Clarita, and western San Fernando Valleys, the weather service said.

From Los Angeles Times • Jun. 8, 2026

Alexander Zverev and Mirra Andreeva claimed their first Grand Slam titles in Paris at a Roland-Garros marked by extreme heat, pouring rain, and shocking upsets.

From The Wall Street Journal • Jun. 8, 2026

Fujimori, on the other hand, said the result showed a "dead heat" and that there will be long "days ahead" to declare a winner.

From BBC • Jun. 8, 2026

More concerningly, they would’ve seen that new spots of heat were coming almost exclusively from around the bulge.

From "Mountain of Fire" by Rebecca E. F. Barone

Related Words

• bake
• boil
• broil
• grill
• ignite
• melt
• reheat
• roast
• sear
• steam
• thaw
• toast
• warm