[ser.geant] n [ME, servant, attendant, sergeant, fr. MF sergent, serjant, fr. L servient-, serviens, prp. of servire to serve] (13c) 1: sergeant at arms
2. obs: an officer who enforces the judgments of a court or the commands of one in authority
3: a noncommissioned officer ranking in the army and marine corps above a corporal and below a staff sergeant and in the air force above an airman first class or senior airman and below a staff sergeant; broadly: noncommissioned officer
4: an officer in a police force ranking in the U.S. just below captain or sometimes lieutenant and in England just below inspector