vapor

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Barely visible or cloudy diffused matter, such as mist, fumes, or smoke, suspended in the air.
2. n. The state of a substance that exists below its critical temperature and that may be liquefied by application of sufficient pressure.
3. n. The gaseous state of a substance that is liquid or solid under ordinary conditions.
4. n. The vaporized form of substance for use in industrial, military, or medical processes.
5. n. A mixture of a vapor and air, as the explosive gasoline-air mixture burned in an internal-combustion engine.
6. n. Archaic Something insubstantial, worthless, or fleeting.
7. n. Archaic A fantastic or foolish idea.
8. n. Archaic Exhalations within a bodily organ, especially the stomach, supposed to affect the mental or physical condition. Used with the.
9. n. Archaic A nervous disorder such as depression or hysteria. Used with the.
10. v. To vaporize.
11. v. To give off vapor.
12. v. To evaporate.
13. v. To engage in idle, boastful talk.

Century Dictionary and Cyclopedia

1. n. An exhalation of moisture; any visible diffused substance, as fog, mist, steam, or smoke, floating in the atmosphere and impairing its transparency.
2. n. In physics, the gaseous form which a solid or liquid substance assumes when sufficiently heated. Vapor is essentially gas, and, since all known gases have now been proved to be liquefiable, no physical difference can be said really to exist between an ordinary gas, such as oxygen, and a vapor, such as steam. In common language, however, a difference is usually recognized: a gas is a substance which at ordinary temperatures and pressures exists in the gaseous state, while a vapor is the gaseous form of a substance which normally exists in a solid or liquid form. An important distinction exists between a saturated vapor (one which is on the point of condensation) and a non-saturated vapor (one which can be compressed or cooled to a certain extent without condensation). The latter obeys Boyle's and Gay-Lussac's laws of gases; in the former, however, increased compression produces condensation, but does not change the pressure of the vapor, which is a function of the temperature alone. Superheated steam is a non-saturated vapor. Aqueous vapor is always present as a minor constituent of the atmosphere, and its amount, which is very variable both at different places on the earth's surface and in the same locality at different times, forms an important element of climate. By a reduction of temperature the aqueous vapor in the air is brought to the socalled state of saturation, and then condensed into cloud, mist, and rain. See rain.
3. n. Effluence; influence.
4. n. Wind; flatulence.
5. n. In medicine, a class of remedies, officinal in the British pharmacopœia, which are to be applied by inhalation: such as vapor creasoti, a mixture of 12 minims of creosote in 8 fluidounces of boiling water, the vapor of which is to be inhaled.
6. n. Something unsubstantial, fleeting, or transitory; vain imagination; fantastic notion.
7. n. plural A hectoring or bullying style of language or conduct, adopted by ranters and swaggerers with the purpose of bringing about a real or mock quarrel.
8. n. plural A disease of nervous debility in which strange images seem to float hazily before the eyes, or appear as if real; hence, hypochondriacal affections; depression of spirit; dejection; spleen; “the blues”: a term much affected in the eighteenth century, but now rarely used.
9. To pass off in the form of vapor; dissolve, as into vapor or thin air; be exhaled; evaporate.
10. To give out vapor, steam, or gas; emit vapors or exhalations; exhale; steam.
11. To boast or vaunt; bully; hector; brag; swagger; bounce.
12. To cause to pass into the state of vapor; cause to dissolve or disappear in or as in vapor, gas, thin air, or other unsubstantial thing.
13. To afflict or infect with vapors; dispirit; depress.
14. To bully; hector.

Wiktionary

1. n. Cloudy diffused matter such as mist, steam or fumes suspended in the air.
2. n. The gaseous state of a substance that is normally a solid or liquid.
3. v. intransitive To become vapor; to be emitted or circulated as vapor.
4. v. transitive To turn into vapor.
5. v. intransitive To use insubstantial language; to boast or bluster.

GNU Webster's 1913

1. n. (Physics) Any substance in the gaseous, or aëriform, state, the condition of which is ordinarily that of a liquid or solid.
2. n. In a loose and popular sense, any visible diffused substance floating in the atmosphere and impairing its transparency, as smoke, fog, etc.
3. n. obsolete Wind; flatulence.
4. n. Something unsubstantial, fleeting, or transitory; unreal fancy; vain imagination; idle talk; boasting.
5. n. An old name for hypochondria, or melancholy; the blues.
6. n. (Pharm.) A medicinal agent designed for administration in the form of inhaled vapor.
7. v. To pass off in fumes, or as a moist, floating substance, whether visible or invisible, to steam; to be exhaled; to evaporate.
8. v. rare To emit vapor or fumes.
9. v. To talk idly; to boast or vaunt; to brag.
10. v. To send off in vapor, or as if in vapor.

WordNet 3.0

1. n. the process of becoming a vapor
2. n. a visible suspension in the air of particles of some substance