Meaning of “Hoist with His Own Petard” phrase of Idiom, definition and synonyms use in sentence.

Hoist with His Own Petard

marshal me to knavery. Let it work; for ’tis good sport to have the engineer hoist with his own petard.”

—SHAKESPEARE : Hamlet,

 Thus Hamlet, in Shakespeare’s play, seeking to foil the designs of the king against him. The phrase means to be caught in one’s own trap.

In the early days of the use of cannon in warfare, the French had a species of artillery called a “petard,” a short, boxlike, iron engine filled with gunpowder. Some, filled with Greek fire, were used as bombs and flung into the ranks of the enemy. Others, much larger, were fixed to a fortress gate, or placed beneath earthworks. The men who operated them, called “petardiers,” were covered from head to heel with armour, for there was always danger of one being blown sky-high by his own weapon—literally hoisted into the air—before he could get clear of the explosion.

Dean Swift once received a turbot as a present. The page had often been on similar errands but had never received the expected • tip. Walking somewhat rudely into the dean’s study and laying the basket on the floor, he said, retiring: “Here’s a turbot for you I” Quick as thought, the dean, determined to teach the boy good manners, called him back, saying : “Here, my lad, take my place and I’ll show you how to deliver a message.” Seating himself in the dean’s chair, the boy sullenly watched the famous Irish wit take up the basket and retire from the room, to return immediately, with the words: “My master presents his kind compliments, and hopes you will be pleased with the acceptance of a small present.” “Does he,” ejaculated the boy, quickly perceiving the situation, “give him my best thanks, and, wait ! here’s something for yourself.” Hoist with his own petard, the dean laughed heartily, and rewarded the boy handsomely for his smartness.