(aviation, of an act or action) With the participants being two or more aircraft in flight. / (aviation, military, of a missile) Fired from an aircraft in flight at another one.

Alternative spelling of on the air, especially when used attributively.

Broadcasting or transmitting through the medium of radio or television. / Being, or so as to be, broadcast or transmitted by radio or television. / Smoothly; gracefully. / Happily.

(broadcasting) Synonym of on air.

Pronunciation spelling of are.

To bring (something) into contact with the air, so as to freshen or dry it. / To let fresh air into a room or a building, to ventilate. / To discuss varying viewpoints on a given topic.

(historical, philosophy, alchemy) understood as one of the four elements of the ancient Greeks and Romans.

Pronunciation spelling of hair.

Alternative spelling of on air, especially when used attributively.

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