A non-commissioned officer in the armed forces of several countries, ranking above a sergeant. (Sometimes abbreviated to "staff").
A non-commissioned officer in the British Army, ranking above a sergeant and below a warrant officer class 2.
A non-commissioned officer in the United States Army, ranking above sergeant and below sergeant first class.
(Marines) A non-commissioned officer in the United States Marine Corps, ranking above sergeant and below gunnery sergeant.
(Air Force) A non-commissioned officer in United States Air Force, ranking above senior airman and below technical sergeant.