air

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A colorless, odorless, tasteless, gaseous mixture, mainly nitrogen (approximately 78 percent) and oxygen (approximately 21 percent) with lesser amounts of argon, carbon dioxide, hydrogen, neon, helium, and other gases.
2. n. This mixture with varying amounts of moisture and particulate matter, enveloping the earth; the atmosphere.
3. n. The sky; the firmament.
4. n. A giant void; nothingness: The money vanished into thin air.
5. n. An atmospheric movement; a breeze or wind.
6. n. Aircraft: send troops to Europe by air.
7. n. Public utterance; vent: gave air to their grievances.
8. n. The electronic broadcast media: "often ridiculed . . . extremist groups on air” ( Christian Science Monitor).
9. n. A peculiar or characteristic impression; an aura.
10. n. Personal bearing, appearance, or manner; mien.
11. n. An affected, often haughty pose; affectation. See Synonyms at affectation.
12. n. Music A melody or tune, especially in the soprano or tenor range.
13. n. Music A solo with or without accompaniment.
14. n. Air conditioning.
15. n. Archaic Breath.
16. v. To expose so that air can dry, cool, or freshen; ventilate.
17. v. To give vent to publicly: airing my pet peeves. See Synonyms at vent¹.
18. v. To broadcast on television or radio: "The ad was submitted to CBS . . . which accepted and aired it” ( New York).
19. v. To be broadcast on television or radio: "tidbits that will air on tonight's 6 o'clock news” ( Terry Ann Knopf).
20. adj. Of or relating to the air or the movement of air: an air tube.
21. adj. Existing or living in the air; aerial.
22. adj. Powered by compressed air: an air horn.
23. adj. Containing or inflated by air.
24. adj. Of or relating to aircraft or aeronautics.
25. adj. Of or relating to the broadcast or transmission of radio or television signals.
26. adj. Imaginary or unreal: "The guy had just hit it big . . . after ten years of eating air sandwiches” ( Jonathan Kellerman).
27. idiom. in the air Abroad; prevalent: Excitement was in the air.
28. idiom. up in the air Not yet decided; uncertain.

Century Dictionary and Cyclopedia

1. n. The respirable fluid which surrounds the earth and forms its atmosphere. It is inodorous, invisible, insipid, colorless, elastic, possessed of gravity, easily moved, rarefied, and condensed, essential to respiration and combustion, and is the medium of sound. It is composed by volume of 21 parts of oxygen and 79 of nitrogen; by weight, of 23 of oxygen and 77 of nitrogen. These gases are not chemically united, but are mixed mechanically. Air contains also of carbon dioxid, some aqueous vapor, and small varying amounts of ammonia, nitric acid, ozone, and organic matter. The specific gravity of the air at 32° F. is to that of water as 1 to 773, and 100 cubic inches at mean temperature and pressure weigh 30½ grains. When air is inhaled into the lungs oxygen is separated from the nitrogen, and, uniting with the carbon in the blood, is expelled as carbon dioxid; it thus serves to purify the blood and furnishes the body with heat. By the ancient philosophers air was considered one of the four elements of all things, and this view was maintained until comparatively recent times.
2. n. In old chemistry, gas: still in use in this sense in foundries and machine-shops, especially for such gases as are mingled with air or formed from it, as the gases from a furnace. In distinction from this use, common air is often called atmospheric air.
3. n. A movement of the atmosphere; a light breeze: usually in the plural.
4. n. Utterance abroad; publication; publicity.
5. n. Hence Intelligence; information; advice.
6. n. The graphic representation, as in a painting, of the effect of the atmospheric medium through which natural objects are viewed.
7. n. In the Gr. Ch., a very thin veil spread over both the paten and the chalice, in addition to the paten and chalice veils. Also called nephele.
8. To expose to the air; give access to the open air; ventilate: as, to air clothes; to air a room.
9. Hence To expose ostentatiously; display; bring into public notice: as, to air one's views.
10. To expose to heat; warm: as, to air linen; to air liquors. reflexive To expose (one's self) to the air.
11. intransitive To take the air.
12. n. The peculiar look, appearance, and bearing of a person: as, the air of a youth; a graceful air; a lofty air.
13. n. The general character or complexion of anything; appearance; semblance.
14. n. plural Affected manner; manifestation of pride or vanity; assumed haughtiness: chiefly in the phrases to put on airs, to give one's self airs.
15. n. plural The artificial motions or carriage of a horse.
16. n. In painting, that which expresses action, manner, gesture, or attitude.
17. n. In music: A rhythmical melody; a tune consisting of single successive notes divided into groups which, in duration, have some definite ratio to one another, recognizable by the ear. A song or piece of poetry for singing: as, the air, “Sound an Alarm.” The soprano part in a harmonized piece of music. Also called aria. Any piece of poetry.
18. To set to music.
19. n. Same as airy, aery.
20. Early.

Wiktionary

1. n. uncountable, historical, astrology, alchemy, sciences The atmospheric substance above the surface of the earth which animals breathe, formerly considered to be a single substance, one of the four basic elements of ancient philosophy and one of the five basic elements of Eastern traditions.
2. n. uncountable, physics, meteorology Now understood as the mixture of gases comprising the earth's atmosphere.
3. n. The apparently open space above the ground; the mass of this substance around the earth.
4. n. A feeling or sense.
5. n. A sense of poise, graciousness, or quality.
6. n. usually plural Pretension; snobbishness; pretence that one is better than others.
7. n. music A song, especially a solo; an aria.
8. n. informal Nothing; absence of anything.
9. n. uncountable An air conditioner or the processed air it produces.
10. n. obsolete, chemistry Any specific gas.
11. n. snowboarding, skateboarding A jump in which one becomes airborne.
12. v. To bring (something) into contact with the air, so as to freshen or dry it.
13. v. To let fresh air into a room or a building, to ventilate.
14. v. To discuss varying viewpoints on a given topic.
15. v. To broadcast, as with a television show.

GNU Webster's 1913

1. n. The fluid which we breathe, and which surrounds the earth; the atmosphere. It is invisible, inodorous, insipid, transparent, compressible, elastic, and ponderable.
2. n. Symbolically: Something unsubstantial, light, or volatile.
3. n. A particular state of the atmosphere, as respects heat, cold, moisture, etc., or as affecting the sensations
4. n. obsolete Any aëriform body; a gas.
5. n. Air in motion; a light breeze; a gentle wind.
6. n. Odoriferous or contaminated air.
7. n. That which surrounds and influences.
8. n. Utterance abroad; publicity; vent.
9. n. obsolete Intelligence; information.
10. n. A musical idea, or motive, rhythmically developed in consecutive single tones, so as to form a symmetrical and balanced whole, which may be sung by a single voice to the stanzas of a hymn or song, or even to plain prose, or played upon an instrument; a melody; a tune; an aria.
11. n. In harmonized chorals, psalmody, part songs, etc., the part which bears the tune or melody -- in modern harmony usually the upper part -- is sometimes called the air.
12. n. The peculiar look, appearance, and bearing of a person; mien; demeanor.
13. n. Peculiar appearance; apparent character; semblance; manner; style.
14. n. An artificial or affected manner; show of pride or vanity; haughtiness.
15. n. The representation or reproduction of the effect of the atmospheric medium through which every object in nature is viewed.
16. n. Carriage; attitude; action; movement.
17. n. (Man.) The artificial motion or carriage of a horse.
18. v. To expose to the air for the purpose of cooling, refreshing, or purifying; to ventilate.
19. v. To expose for the sake of public notice; to display ostentatiously.
20. v. To expose to heat, for the purpose of expelling dampness, or of warming

WordNet 3.0

1. v. expose to cool or cold air so as to cool or freshen
2. v. broadcast over the airwaves, as in radio or television
3. n. a distinctive but intangible quality surrounding a person or thing
4. n. the region above the ground
5. v. expose to warm or heated air, so as to dry
6. n. travel via aircraft
7. n. the mass of air surrounding the Earth
8. n. a succession of notes forming a distinctive sequence
9. n. once thought to be one of four elements composing the universe (Empedocles)
10. v. be broadcast
11. v. expose to fresh air
12. n. medium for radio and television broadcasting
13. n. a mixture of gases (especially oxygen) required for breathing; the stuff that the wind consists of
14. v. make public
15. n. a slight wind (usually refreshing)