1. U.S. Air Force.a uniform consisting of the coat and trousers of the service uniform, with a white shirt and black bow tie, worn for formal occasions.
2. U.S. Army.a blue uniform worn for formal occasions.
3. U.S. Navy.a dark blue uniform worn in cool seasons or climates.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.