From Longman Dictionary of Contemporary Englishstaff sergeantˈstaff ˌsergeant noun [countable, uncountable] PMAPMPa lower rank in the army or the US Air Force or Marines, or someone who has this rank
Examples from the Corpus
staff sergeant• Carter, a staff sergeant who worked in a Los Angeles tire facility after the war, passed away in 1963.• Turner exchanged a glance with his staff sergeant. 