Definition of: heat

(hēt) noun
1. That which raises the temperature of a body or substance or any material system; also the rise itself, however produced.
2. Physics A form of energy directly associated with and proportional to the random molecular motions of a substance or body; it may be variously generated (as by combustion, friction, chemical action, radiation, etc.), converted by suitable processes into other forms of energy, and its total absence corresponds with that complete cessation of all translational molecular motion known as absolute zero. ♦ Collateral adjective: thermal.
3. The sensation produced by a rise in temperature.
4. The state of being hot; a temperature high as compared with a mean, standard, or normal temperature: summer heat.
5. Color, appearance, or condition indicating high temperature; high color; redness; flush.
6. Metall. A single heating, melting, or smelting operation, as in working iron or steel; also, the material heated, melted, etc., at one time: The foundry runs three heats a day.
7. A single effort or action, or one of an interrupted series of such efforts; especially, a single course or division of a race: to run several heats.
8. Greatest vehemence or fury; excitement or agitation; unusual animation; ardor; fervency: the heat of battle.
9. Sexual excitement in animals, especially in females; estrus.
10. Physiol. The sensation of warmth experienced when certain receptors in the skin are stimulated.
11. A fundamental quality of elements, humors, and bodies in general: opposed to cold. See synonyms under WARMTH.
—v.t. & v.i.
1. To make or become hot or warm.
2. To excite or become excited; arouse. See synonyms under INCENSE. [OE hatu]
—heat′ed adjective
—heat′ed·ly adverb