a person of any gender with undeniable beauty/ someone who makes others want to jump on them and lick their face/ a person who is incredibly attractive and has the ability to make you drool by just looking at them
Laura: ooh, check out that boy in the blue top over there
Kelly: wow, he is a real hoisty mcshving!
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."