petard

1. 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。
2. It was indeed a clever plan to entrap his opponent, but in the end he was hoist by his own petard.
   设圈套陷害他的对手固然是个妙计，可是到头来却是害人反害己。
3. Your tenure and cost to the organization ( 30%): how much money could the company save if it hoisted you by your expensive petard?
   员工任期及公司在此期间花在你身上的成本（30%）：如果公司以聘用你的成本过高为理由炒你的鱿鱼，公司能够节省多少开支？
4. The reality is that Gawker and sites such as Mail Online, drawn from the UK tabloid tradition, face being hoist by their own petard.
   现实是Gawker及脱胎于英国小报传统的MailOnline这类网站正面临自食其果的窘境。
5. The criminal was hoist with his own petard when he tried to kill his master, because he accidentally drank the poison that he intended to give to him.
   那罪犯试图谋杀师傅时，反而害了自己，因为他意外地喝下了他欲给师傅的毒药。
6. The police hoisted the criminal with his own petard.
   警察使罪犯搬起石头砸自己的脚。

n.

be hoist/hoisted by/with your own petard

• 害人反害己；自食其果
  to be hurt or to have problems as a result of your own plans to hurt or trick others

noun

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