command'er in chief'
—pl. commanders in chief.
1. Also,Command'er in Chief'.the supreme commander of the armed forces of a nation or, sometimes, of several allied nations: The president is the Commander in Chief of the U.S. Army, Navy, and Air Force.
2. an officer in command of a particular portion of an armed force who has been given this title by specific authorization.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.