air

n. & v.
—n.
1 an invisible gaseous substance surrounding the earth, a mixture mainly of oxygen and nitrogen.
2 a the earth's atmosphere. b the free or unconfined space in the atmosphere (birds of the air; in the open air). c the atmosphere as a place where aircraft operate.
3 a a distinctive impression or characteristic (an air of absurdity). b one's manner or bearing, esp. a confident one (with a triumphant air; does things with an air). c (esp. in pl.) an affected manner; pretentiousness (gave himself airs; airs and graces).
4 Mus. a tune or melody; a melodious composition.
5 a breeze or light wind.
—v.tr.
1 warm (washed laundry) to remove damp, esp. at a fire or in a heated cupboard.
2 expose (a room etc.) to the open air; ventilate.
3 express publicly (an opinion, grievance, etc.).
4 parade; show ostentatiously (esp. qualities).
5 refl. go out in the fresh air.
Phrases and idioms:
air bag a safety device that fills with air on impact to protect the occupants of a vehicle in a collision. air-bed an inflatable mattress. air-bladder a bladder or sac filled with air in fish or some plants (cf. swim-bladder). air brake
1 a brake worked by air pressure.
2 a movable flap or other device on an aircraft to reduce its speed. air-brick a brick perforated with small holes for ventilation. air-bridge a portable bridge or walkway put against an aircraft door. Air Chief Marshal an RAF officer of high rank, below Marshal of the RAF and above Air Marshal. Air Commodore an RAF officer next above Group Captain. air-conditioned (of a room, building, etc.) equipped with air-conditioning. air-conditioner an air-conditioning apparatus.
air-conditioning
1 a system for regulating the humidity, ventilation, and temperature in a building.
2 the apparatus for this. air-cooled cooled by means of a current of air. air corridor = CORRIDOR 4. air-cushion 1 an inflatable cushion.
2 the layer of air supporting a hovercraft or similar vehicle. air force a branch of the armed forces concerned with fighting or defence in the air. air-hostess a stewardess in a passenger aircraft. air lane a path or course regularly used by aircraft (cf. LANE 4). air letter a sheet of light paper forming a letter for sending by airmail. air line a pipe supplying air, esp. to a diver. Air Marshal an RAF officer of high rank, below Air Chief Marshal and above Air Vice-Marshal. Air Officer any RAF officer above the rank of Group Captain. air plant a plant growing naturally without soil. air pocket an apparent vacuum in the air causing an aircraft to drop suddenly. air power the ability to defend and attack by means of aircraft, missiles, etc. air pump a device for pumping air into or out of a vessel. air raid an attack by aircraft. air rifle a rifle using compressed air to propel pellets. air sac an extension of the lungs in birds or the tracheae in insects. air-sea rescue rescue from the sea by aircraft. air speed the speed of an aircraft relative to the air through which it is moving. air terminal a building in a city or town to which passengers report and which serves as a base for transport to and from an airport. air time time allotted for a broadcast. air-to-air from one aircraft to another in flight. air traffic controller an airport official who controls air traffic by giving radio instructions to pilots concerning route, altitude, take-off, and landing. Air Vice-Marshal an RAF officer of high rank, just below Air Marshal. air waves colloq. radio waves used in broadcasting. by air by aircraft; in an aircraft.
in the air
1 (of opinions or feelings) prevalent; gaining currency.
2 (of projects etc.) uncertain, not decided. on (or off) the air in (or not in) the process of broadcasting. take the air go out of doors. tread (or walk) on air feel elated.
Etymology: ME f. F and L f. Gk aer