GAS [U] › the mixture of gases around the Earth which we breathe: air pollution He went outside to get some fresh air (= clean, cool air).
the air › the space above and around things: He fired his gun into the air.
TRAVEL [U] › travel in an aircraft: I like travelling by air. air safety QUALITY [no plural] › a particular appearance or quality: He has an air of authority.
be on air › to be broadcasting on television or radio → See also a breath of fresh air → See also mid-air