–noun

1.	a mixture of nitrogen, oxygen, and minute amounts of other gases that surrounds the earth and forms its atmosphere.

2.	a stir in the atmosphere; a light breeze.

3.	overhead space; sky: The planes filled the air.

4.	circulation; publication; publicity: to give air to one's theories.

5.	the general character or complexion of anything; appearance: His early work had an air of freshness and originality.

6.	the peculiar look, appearance, and bearing of a person: There is an air of mystery about him.

7.	airs, affected or unnatural manner; manifestation of pride or vanity; assumed haughtiness: He acquired airs that were insufferable to his friends.

8.	Music. a. a tune; melody. b. the soprano or treble part. c. an aria. d. Also, ayre. an Elizabethan art song.

9.	aircraft as a means of transportation: to arrive by air; to ship goods by air.

10.	Informal. air conditioning or an air-conditioning system: The price includes tires, radio, and air.

11.	Radio. the medium through which radio waves are transmitted.

12.	Archaic. breath.

–verb (used with object)

13.	to expose to the air; give access to the open air; ventilate (often fol. by out): We air the bedrooms every day.

14.	to expose ostentatiously; bring to public notice; display: to air one's opinions; to air one's theories.

15.	to broadcast or televise.

–verb (used without object)

16.	to be exposed to the open air (often fol. by out): Open the window and let the room air out.

17.	to be broadcast or televised.

–adjective

18.	operating by means of air pressure or by acting upon air: an air drill; an air pump.

19.	of or pertaining to aircraft or to aviation: air industry.

20.	taking place in the air; aerial: air war.

—Idioms

21.	clear the air, to eliminate dissension, ambiguity, or tension from a discussion, situation, etc.: The staff meeting was intended to help clear the air.

22.	get the air, Informal. a. to be rejected, as by a lover. b. to be dismissed, as by an employer: He had worked only a few days when he got the air.

23.	give (someone) the air, Informal. a. to reject, as a lover: He was bitter because she gave him the air. b. to dismiss, as an employee.

24.	in the air, in circulation; current: There's a rumor in the air that we're moving to a new location.

25.	into thin air, completely out of sight or reach: He vanished into thin air.

26.	off the air, a. not broadcasting: The station goes off the air at midnight. 1c1 b. not broadcast; out of operation as a broadcast: The program went off the air years ago. c. (of a computer) not in operation.

27.	on the air, a. in the act of broadcasting; being broadcast: The program will be going on the air in a few seconds. b. (of a computer) in operation.

28.	put on airs, to assume an affected or haughty manner: As their fortune increased, they began to put on airs.

29.	take the air, a. to go out-of-doors; take a short walk or ride. b. Slang. to leave, esp. hurriedly. c. to begin broadcasting.

30.	up in the air, a. Also, in the air. undecided or unsettled: The contract is still up in the air. b. Informal. angry; perturbed: There is no need to get up in the air over a simple mistake.

31.	walk or tread on air, to feel very happy; be elated.

–noun Chiefly Western U.S.

1.	a dry riverbed.

2.	a small, deep canyon.