Word Origin & History
1598, "small bomb used to blow in doors and breach walls," from Fr. pétard (1580), from M.Fr. péter "break wind," from O.Fr. pet "a fart," from L. peditum, properly neut. pp. of pedere "to break wind" (in M.L. pettus). Surviving in phrase hoist with one's own petard (or some variant) "blown
up with one's own bomb," which is ult. from Shakespeare (1605):
"For tis the sport to haue the enginer Hoist with his owne petar" ("Hamlet" III.iv.207).