Do you know ghouls from goblins and ghosts?
early 14c., from Old French venquis (past tense), and vencus (p.p.), from veintre "defeat," from Latin vincere "defeat" (see victor). Influenced in Middle English by Middle French vainquiss-, present stem of vainquir "conquer," from Old French vainkir, alteration of veintre. Related: Vanquished; vanquishing.