ser·geant / ˈsärjənt/ • n. a noncommissioned officer in the armed forces, in particular (in the U.S. Army or Marine Corps) an NCO ranking above corporal and below staff sergeant, or (in the U.S. Air Force) an NCO ranking above airman and below staff sergeant. ∎ Brit. a police officer ranking below an inspector. ∎  a police officer ranking below a lieutenant.DERIVATIVES: ser·gean·cy / -jənsē/ n. (pl. -cies) .

sergeant, serjeant †servant XII; †common soldier; †tenant by military service below a knight; officer charged with the arrest of offenders, etc. (now in s. at arms); (after law L. serviens ad lēgem serjeant-at-law) XIII; officer of the Corporation of London XV; military non-commissioned officer XVI. — OF. sergent, serjant (mod. sergent) :- L. servientem (see -ANT), prp. of servīre SERVE (cf. SERVANT). The form with j has become appropriated to leg. use.