A commander-in-chief is the person or body exercising supreme operational command and control of a nation`s military forces or significant elements of those forces. In the latter case, the force element may be defined as those forces within a particular region or those forces which are associated by function. As a practical term it refers to the ....
[n] - the officer who holds the supreme command
generalissimo noun the officer who holds the supreme command; `in the U.S. the president is the commander 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. · an officer in command of a particular portion of an armed force who has been given this title by specific authorization.