air

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun 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.
• noun This mixture with varying amounts of moisture and particulate matter, enveloping the earth; the atmosphere.
• noun The sky; the firmament.
• noun A giant void; nothingness.
• noun An atmospheric movement; a breeze or wind.
• noun Sports A height achieved by a jump or as part of an airborne maneuver, as in skateboarding or snowboarding.
• noun Aircraft.
• noun Public utterance; vent.
• noun The medium of broadcast radio or television.
• noun A manner of behaving that conveys an impression.
• noun A distinctive quality or appearance; an aura.
• noun The general environment or condition, as in attitudes and ideas.
• noun Affected behavior; affectation: synonym: affectation.
• noun A melody or tune, especially in the soprano or tenor range.
• noun A solo with or without accompaniment.
• noun Air conditioning.
• noun Archaic Breath.
• intransitive verb To expose to the air in order to dry, cool, or freshen; ventilate.
• intransitive verb To make known to others; express publicly: synonym: voice.
• intransitive verb To broadcast on television or radio.
• intransitive verb To be broadcast on television or radio.
• adjective Of or relating to the air or the movement of air.
• adjective Existing or living in the air; aerial.
• adjective Powered by compressed air.
• adjective Containing or inflated by air.
• adjective Of or relating to aircraft or aeronautics.
• adjective Of or relating to the broadcast or transmission of radio or television signals.
• adjective Imaginary or unreal.
• idiom Football (air one out) To throw a long pass.
• idiom (in the air) Abroad; prevalent.
• idiom (up in the air) Not yet decided; uncertain.

from The Century Dictionary.

• To expose to the air; give access to the open air; ventilate: as, to air clothes; to air a room.
• Hence To expose ostentatiously; display; bring into public notice: as, to air one's views.
• To expose to heat; warm: as, to air linen; to air liquors. reflexive To expose (one's self) to the air.
• intransitive To take the air.
• noun 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.
• noun The peculiar look, appearance, and bearing of a person: as, the air of a youth; a graceful air; a lofty air.
• noun The general character or complexion of anything; appearance; semblance.
• noun plural Affected manner; manifestation of pride or vanity; assumed haughtiness: chiefly in the phrases to put on airs, to give one's self airs.
• noun plural The artificial motions or carriage of a horse.
• noun In painting, that which expresses action, manner, gesture, or attitude.
• noun The respirable fluid which surrounds the earth and forms its atmosphere.
• noun 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.
• noun A movement of the atmosphere; a light breeze: usually in the plural.
• noun Utterance abroad; publication; publicity.