adj. phr. Caught in your own trap or trick. Jack carried office gossip to the boss until he was hoisted by his own petard. (From Shakespeare; literally, blown up with one's own bomb.)
HOIST WITH ONE'S OWN PETARD
Meaning of HOIST WITH ONE'S OWN PETARD in English
American idioms English vocabulary. Английский словарь американских идиом. 2012