To be foiled by your own advantage(i.e., explosives prematurely explode).
The history of the phrase comes from the uses of a petard in a seige (a petard is a volitile early explosive capable of bringing down castle walls). To be hoisted is to be lifted or sent up, which is generally what would happen to you if you were near a petard when it goes off (and that's if you got off lucky).
The term, "Hoisted on my own petard" is incorrect (unless of course you were pulled up while on a petard, but that'd be clinicly stupid) in that the meaning is altered. This bastardization is built upon the assumtion that a petard is a spear.
Sergeant- "Did you plant all the claymores Corporal Johnson?"
Corporal- "Yes sir."
Sergeant- "Where did you plant them."
Corporal- *Looks around shiftily* "Ummmm..."
Sergeant- "You don't know do you?"
Corporal- "No."
Sergeant- "Hoisted by my own petard."
A sunburn or suntan focused on the left arm. It is caused by the left side of the body being the only half that gets exposed to sunlight while driving. Presumably, it would be located on the right side of the body in countries where they drive on the left side of the road.
British slang for a scientist or technical expert, esp . when the speaker is not certain of the expert’s specific field of study. Not necessarily derogatory, but typically used by persons without a technical background. In the US, the equivalent would be “egghead”, “squint”, or “geek.”
Origin of the word is unknown. Started sometime in World War 2. Given the typical evolution of British slang, could easily have started because what these experts did was confusing or “baffling” to the common person.
When you have to pee in a movie but don’t want to miss anything, and must do the following mental equation: will the amount I have to pee cause enough discomfort to diminish my attention capacity for the remainder of the movie to an extent which is greater than the amount of the movie I would miss by making a mad dash to the restroom.
I saw Satantango last night, wonderful film but by the 5th hour I had to start doing peecalculus.