master sergeant

noun3

1. •
   (US) A non-commissioned officer in the United States Army, ranking above sergeant first class and below sergeant major; equal in grade and pay to a first sergeant.
2. •
   (US) A non-commissioned officer in the United States Marine Corps, ranking above gunnery sergeant and below master gunnery sergeant or sergeant major.
3. •
   (US) A non-commissioned officer in the United States Air Force, ranking above technical sergeant and below senior master sergeant.