名词（古代）攻城炸药箱，爆竹

1. 爆竹：petalled 有花瓣的 | petard 爆竹 | petasos 宽边帽

2. 爆炸装置：Organ Gun 排砲 | Petard 爆炸裝置 | Ram 撞槌

3. 破門裝置：花瓣式列印機 petal printer | 破門裝置 petard | 小型網路 Petri net

4. 炸药的一种/花火/爆竹：petals /翼瓣/ | petard /炸药的一种/花火/爆竹/ | petasma /雄交接器/

1. 七彩网.英语单词

1. 害人反害己；自食其果
If someone who has planned to harm someone else is hoist with their own petard or hoist by their own petard, their plan in fact results in harm to themselves.

e.g. The students were hoist by their own petards, however, as Granada decided to transmit the programme anyway.
不过，学生们聪明反被聪明误，格拉纳达最终还是决定要转播这个节目。

noun

1. an explosive device used to break down a gate or wall