"Hoist one with his own petard" is an idiomatic phrase that means to be hurt or defeated by one's own plan, or to fall into one's own trap. There are several synonyms for this phrase, such as "getting a taste of one's own medicine", "backfiring on oneself", "having the tables turned on oneself", and "receiving one's comeuppance". Each of these phrases has a slightly different connotation, but they all convey the idea that someone is experiencing the consequences of their own actions. These phrases serve as a reminder to think carefully before engaging in any action, as it may come back to haunt you in the end.