sergeant-major
noun
Definitions
A senior non-commissioned appointment in the Army of a company or unit, directly responsible to the officer in charge for their soldiers' performance, standards, discipline, morale, welfare, et al, that can be held by a Warrant Officer or above.
(plural sergeants major) The most senior rank of non-commissioned officer in the United States Army, ranking above a first sergeant. In the United States Marine Corps it ranks above First Sergeant and is equal in grade to Master Gunnery Sergeant.
(plural sergeant majors) An appointment (not a rank) in the British Army and Royal Marines, denoting the most senior non-commissioned officer in a battalion, regiment or company.
(plural sergeant majors) An appointment (not a rank) in the Singapore Army and National Cadet Corps, denoting the most senior non-commissioned officer in a battalion, regiment, company or unit.