staff sergeant

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A noncommissioned rank in the US Army that is above sergeant and below sergeant first class.
• noun A noncommissioned rank in the US Air Force that is above senior airman and below technical sergeant.
• noun A noncommissioned rank in the US Marine Corps that is above sergeant and below gunnery sergeant.
• noun One who holds the rank of staff sergeant.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

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

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a noncommissioned officer ranking above corporal and below sergeant first class in the Army or Marines or above airman 1st class in the Air Force