origin: Old French, from "péter"; to break wind, from "pet"; a breaking of wind. Latin, "pēdere".
1. Bell-shaped bomb used to break open gates and/or walls.
2. A loud, explosive firework.
A nod to member uniquepov, for you may be familiar with this word specifically from the ever-so-useful and frequently apt phrase: "Hoisted on your own petard!" *originating in Hamlet (1602)
Meaning: to blow oneself up with one's own bomb, be undone by one's own devices.