(pe-TAHRD, pi-)

1. A small bomb used to blast down a gate or wall.
2. A loud firecracker.

From French péter (to break wind), from Latin peditum (a breaking wind), from pedere (to break wind). Ultimately from the Indo-European root pezd- (to break wind) which also gave us feisty, fart, and French pet (fart). Earliest documented use: 1566.

A petard was a bell-shaped bomb used to breach a door or a wall. Now that we have advanced to ICBMs, this low-tech word survives in the phrase "to hoist by one's own petard" meaning "to have one's scheme backfire". The idiom was popularized by Shakespeare in his play Hamlet. Hamlet, having turned the tables on those tasked with killing him, says:
For 'tis the sport to have the engineer
Hoist with his own petard


PETYARD = a Chinese abbatoir