In the surrounding ambience. / In the generally prevailing feeling, idea, atmosphere, or mood. / Prevalent without traceable origin or authority.

Alternative spelling of on air, especially when used attributively.

A clothes storage cupboard built around a house's hot water system, using the heat to dry damp clothes.

present participle of air out

plural of airing cupboard

(military) A missile that is fired from an aircraft to attack another aircraft.

plural of air-to-air missile

The bilateral agreements concerning international air travel defined by the Chicago Convention in 1944, covering such topics as overflight, stopovers, and passenger carriage.

Used other than figuratively or idiomatically: see up, in, the, air.

(idiomatic) Not yet resolved, finished, answered, decided or certain.