1. the U.S. department consisting of practically all military aviation forces, established July 26, 1947.
2. ( l.c. ) a similar department in any military organization.
3. ( l.c. ) (formerly) the largest unit in the U.S. Army Air Forces.
4. ( l.c. ) a unit of U.S. Air Force command between an air division and an air command.
5. ( sometimes l.c. ) the military unit of a nation charged with carrying out military operations in the air.
6. Brit. Royal Air Force.
[ 1915-1920 ]