Definition of "anti-aircraft"

Special lamps were provided for working during the blackout, and an anti-aircraft gun, manned by the R.A.O.C., was mounted on the coal depot line.

1947 January and February, “Wartime Traffic at Tanfield, L.N.E.R.”, in Railway Magazine, page 47

Truth's ships are clustered above the excavation site. And his infantry has deployed anti-aircraft batteries around the perimeter.

2007 September 25, Bungie, Halo 3, v1.0, Microsoft Game Studios, Xbox 360, level/area: Crow's Nest

I am blacking out—ease the stick forward slightly—the sky is clear again—I turn out over water—reverse turn—there are antiaircraft on the island below—I reverse again—and again.

1944 June 3, Charles A. Lindbergh, The Wartime Journals of Charles A. Lindbergh, New York: Harcourt Brace Jovanovich, published 1970, page 839