Do you know ghouls from goblins and ghosts?
kind of machine gun, from French mitrailleuse (19c.), from Old French mitaille (14c.) "small coins," hence "old iron, scrap iron," then "grapeshot;" originally a diminutive of mite "a small coin" (see mite (n.2)). "For sense development it should be borne in mind that orig. guns used to be loaded with scrap iron" [Klein].