petard
Noun: 1. A small explosive device, typically a metal box, used historically to blast through gates, doors, or walls. It functions by being placed against or attached to the obstacle it is intended to breach.
The word "petard" is now almost exclusively used in the historical context of warfare or siegecraft, or in its modern, figurative sense found in the idiom "hoist with one's own petard." It is a formal and somewhat literary term.
Historical/Literal Usage:
- The soldiers used a petard to breach the castle's heavy wooden gate.
- The design of the petard made it a dangerous weapon for the user as well as the target.
Figurative Usage (in the common idiom):
- The schemer was hoist with his own petard when the trap he set for his rival caught him instead.
- The lawyer's attempt to use a technicality backfired, and she was hoist by her own petard.
- Hoist with (or by) one's own petard: This is the primary modern usage of the word. It means to be harmed or defeated by one's own plan or device intended to harm someone else. The phrase originates from Shakespeare's ("For ’tis the sport to have the engineer / Hoist with his own petard"). "Hoist" here means "lifted" or "blown up."
- Petardier (noun, historical): A soldier responsible for placing and detonating petards.
- Explosive charge
- Demolition charge
- Blasting device
The core meaning of "petard" is a specific type of explosive breaching tool. Its contemporary relevance is almost entirely tied to the idiom "hoist with one's own petard," which uses the historical device as a metaphor for a plan that backfires on its creator.
- an explosive device used to break down a gate or wall