vapor

va·por  (vpr)

n.

1. Barely visible or cloudy diffused matter, such as mist, fumes, or smoke, suspended in the air.

2.

a. The state of a substance that exists below its critical temperature and that may be liquefied by application of sufficient pressure.

b. The gaseous state of a substance that is liquid or solid under ordinary conditions.

3.

a. The vaporized form of a substance for use in industrial, military, or medical processes.

b. A mixture of a vapor and air, as the explosive gasoline-air mixture burned in an internal-combustion engine.

4. Archaic

a. Something insubstantial, worthless, or fleeting.

b. A fantastic or foolish idea.

5. vapors Archaic

a. Exhalations within a bodily organ, especially the stomach, supposed to affect the mental or physical condition. Used with the.

b. A nervous disorder such as depression or hysteria. Used with the.

v. va·pored, va·por·ing, va·pors

v.tr.

To vaporize.

v.intr.

1. To give off vapor.

2. To evaporate.

3. To engage in idle, boastful talk.

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[Middle English vapour, from Anglo-Norman, from Latin vapor.]

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vapor·er n.

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vapor

Noun

US same as vapour

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vapor  (vpr)

1. The gaseous state of a substance that is normally liquid or solid at room temperature, such as water that has evaporated into the air. See more at vapor pressure, See also water vapor.

2. A faintly visible suspension of fine particles of matter in the air, as mist, fumes, or smoke.

3. A mixture of fine droplets of a substance and air, as the fuel mixture of an internal-combustion engine.

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vaporize verb

Usage The words vapor and steam usually call to mind a fine mist, such as that in the jet of water droplets near the spout of a boiling teakettle or in a bathroom after a shower. Vapor and steam, however, refer to the gaseous state of a substance. The fumes that arise when volatile substances such as alcohol and gasoline evaporate, for example, are vapors. The visible stream of water droplets rushing out of a teakettle spout is not steam. As the gaseous state of water heated past its boiling point, steam is invisible. Usually, there is a space of an inch or two between the spout and the beginning of the stream of droplets. This space contains steam. The steam loses its heat to the surrounding air, then falls below the boiling point and condenses in the air as water droplets. All liquids and solids give off vapors consisting of molecules that have evaporated from the substance. In a closed system, the vapor pressure of these molecules reaches an equilibrium at which the substance evaporates from the liquid (or solid) and recondenses on it in equal amounts.

Thesaurus

Noun	1.	vapor - a visible suspension in the air of particles of some substance vapour suspension - a mixture in which fine particles are suspended in a fluid where they are supported by buoyancy steam - water at boiling temperature diffused in the atmosphere water vapor, water vapour - water in a vaporous form diffused in the atmosphere but below boiling temperature
	2.	vapor - the process of becoming a vapor evaporation, vaporisation, vaporization, vapour boiling - the application of heat to change something from a liquid to a gas clouding, clouding up - the process whereby water particles become visible in the sky phase change, phase transition, physical change, state change - a change from one state (solid or liquid or gas) to another without a change in chemical composition smoke, smoking - a hot vapor containing fine particles of carbon being produced by combustion; "the fire produced a tower of black smoke that could be seen for miles"