Etymology

Noun

1. The atmospheric substance above the surface of the earth which animals breathe, formerly considered to be a single substance, one of the four basic elements of ancient philosophy and one of the five basic elements of Eastern traditions.
2. Now understood as the mixture of gases comprising the earth's atmosphere.

   The karate instructor said "air is the one thing you can't go five minutes without; when you spar, you have to remember to breathe."

3. The apparently open space above the ground; the mass of this substance around the earth.

   The flock of birds took to the air.

   There was a tension in the air which made me suspect an approaching storm.

4. A feeling or sense.

   ...to give it an air of artistry and sophistication.

5. A sense of poise, graciousness, or quality.
   • 1815, Jane Austen, Emma, Volume I, Chapter 4:

     "He is very plain, undoubtedly--remarkably plain:--but that is nothing compared with his entire want of gentility. I had no right to expect much, and I did not expect much; but I had no idea that he could be so very clownish, so totally without air. I had imagined him, I confess, a degree or two nearer gentility."

6. Pretension; snobbishness; pretence that one is better than others.
   • ...putting on airs...
7. A song, especially a solo; an aria.
   • 1813, Jane Austen, Pride and Prejudice, Chapter 18:

     "If I," said Mr. Collins, "were so fortunate as to be able to sing, I should have great pleasure, I am sure, in obliging the company with an air; for I consider music as a very innocent diversion, and perfectly compatible with the profession of a clergyman..."

8. An air conditioner or the processed air it produces.

   Could you turn on the air?

9. Any specific gas.
10. A jump in which one becomes airborne.

Verb

1. To bring (something) into contact with the air, so as to freshen or dry it.
2. To let fresh air into a room or a building, to ventilate.

   It's getting quite stuffy in this room: let's open the windows and air it.

3. To discuss varying viewpoints on a given topic.
   • 1917, National Geographic, v.31, March 1917:

     Thus, in spite of all opposition, the rural and urban assemblies retained the germ of local government, and in spite of the dual control, as the result of which much of their influence was nullified, they did have a certain value in airing abuses and suggesting improvements.

4. To broadcast, as with a television show.