Function: noun
Inflected Form: plural sergeants major or sergeant majors
Date: 1797
1 : a noncommissioned officer in the army or marine corps serving as chief administrative assistant in a headquarters
2 : a noncommissioned officer in the marine corps ranking above a first sergeant
3 : a bluish-green to yellow bony fish ( Abudefduf saxatilis of the family Pomacentridae) with black vertical stripes on the sides that is widely distributed in the western tropical Atlantic Ocean