petard

That's not a typo as far as I can tell; it appears on a number of other sites in the Shakespeare quotation. (Though as I said, I didn't check any actual books. Of course editors of Shakespeare occasionally change spellings... sigh...)

C_b, did Shakespeare write (in the quotation) "petar"? Or is that a typo (whether yours or Wikipedia's)?

Looks like it can be stated at least two ways, though "by" is more common these days, it seems to be agreed-upon that Shakespeare originated the phrase, and in Hamlet it's "with." This is from Wikipedia (admittedly not the best source, but my Shakespeare books are all in storage so I can't check the veracity):

"The word remains in modern usage in the phrase to be hoist by one's own petard (or to be hoist with one's own petard), which means "to be harmed by one's own plan to harm someone else" or "to fall in one's own trap", literally implying that one could be lifted up (hoisted, or blown upward) by one's own bomb. Shakespeare used the now proverbial phrase in Hamlet.

"In the following passage, the "letters" refer to instructions (written by his uncle Claudius, the King) to be carried sealed to the King of England, by Hamlet, Rosencrantz and Guildenstern, the latter being two schoolfellows of Hamlet. The letters, as Hamlet suspects, contain a death warrant against Hamlet, who will later open and modify them to instead request the execution of Rosencrantz and Guildenstern. Enginer refers to a military engineer, the spelling reflecting Elizabethan stress.

There's letters seal'd: and my two schoolfellows,
Whom I will trust as I will adders fang'd,
They bear the mandate; they must sweep my way
And marshal me to knavery. Let it work;
For 'tis the sport to have the enginer
Hoist with his own petar; and 't shall go hard
But I will delve one yard below their mines
And blow them at the moon: O, 'tis most sweet,
When in one line two crafts directly meet."
(Hamlet, Act 3, scene iv, 202-209)

A brief perusal of other sites that quote Shakespeare directly also use "with." Don't make me no nevermind though. Just posting for Wordieternity. :)

thanks for the apt correction, jmp!

'By' is what I thought, jmp, but I wasn't confident enough to comment.

the phrase is "hoist {or hoised} by his own petard". Not on, not with, but by.

Petard is an explosive mine; to hoise = to blow up.

I was taught this phrase in secondary / high school by my English teacher, but I always assumed a petard was something related to the gallows, specifically the crosspiece I suppose.

Arby--petard sounds like Picard if you're a bit liberal with the pronunciation.

I actually thought it meant "hoisted by one's underwear on the end of a long pointy thing kind of like a sword but stronger."

I was rather imaginative.

Underwear! Me too!

Curiously, I never made the connection with explosives in the phrase "hoisted with his own petard"; I think I thought it was some kind of sword. This despite the fact that I knew that in Slovene petarda means "firecracker".

arby--your reference to being hung up by underwear? Yeah. That's what I thought for many years too. Hee! (glad I wasn't alone...)

Oh and yes, I know the rhyme's not exact. I don't pronounce it PEE-tard.

PS skipvia I don't get it, what's The Enterprise ref. I'm thinking of the latest and most horrible Star Trek series - and to me that totally makes sense because I hate Scott Bakula and find him retarded.

Good grief! And I had no idea either. In my world it was a nickname for the family aardvark.

I associate it with The Enterprise.

I associate this word with two things: 1) retard, simply due to the rhyme, and 2) wedgies - I always thought a petard was like a Renaissance garment, and hoisting by one's petard meant being hung up by one's underwear. I know this makes no sense in the actual sense of the phrase (which is analogous to cutting off your nose to spite someone else's face) but I secretly like my definition better.

When I was growing up, my folks would sometimes say something like, "Looks like so-and-so was hoisted on his own petard." It could be considered poetic justice to be hoisted on one's own petard.

I did not realize it was yet another phrase from Shakespeare.

Wow. And here I was thinking this word was akin to leotard. ;-)

I had to look this up to see if it's a tangible object--apparently it's a bomb, which I did not know--and the phrase "hoist with his own petard" (Shakespeare) means "Blown into the air by his own bomb; hence, injured or destroyed by his own device for the ruin of others." (OED) I had no idea.