bachelors-at-arms

1297, "youthful knight, novice in arms," from O.Fr. bacheler "knight bachelor," a young squire in training for knighthood, probably from M.L. baccalarius "vassal farmer," one who helps or tends a baccalaria "section of land." Or from L. baculum "a stick," since the squire would practice with a staff, not a sword. Meaning evolved 14c. from "knight in training" to "junior member of a guild or university" to "unmarried man" (1386). Fem. form bachelorette, with Fr. ending, is from 1935, replacing earlier bachelor-girl (1895). Bachelor party is first recorded 1922. A clipped form bach was a colloquial verb in 19c. Amer.Eng. meaning "to live as an unmarried man."