An adjective that means you do so many drugs that your brain is permanently fried. You forget how to do easy things, like remember to go to class or put your car in park.
When you "roast" the douchebag at the party multiple times; fucking the party pooper's shit up; wrecking his shit so much he doesn't even know it's happening.
To be in or produce a permanent state of contextual existance in which parties involved are completely and utterly fucked, with no conceivable reprieve and from which there is no escape. See also FUBAR
Guy 1: So how'd your GF know you were cheating? You get ratted out?
Guy 2: No she's got a videotape.
Guy 1: Dude, you're permafucked.
A gangmember rapes a hooker in an alley. Little does he know that the hooker has AIDS. Now he's facing charges of sexual assault, the pimp wants revenge and on top of it all he's gonna die from AIDS in a couple of years. You don't get more permafucked than that.
An truncated version of the phrase "perfectly fucked", similiar to fubar, and snafu perfucked is a situational modifier used to describe an event that ends in catastrophe, or disaster.
"At the time eating eight cupcakesin a row seemed like a good idea, but soon Wade's stomach became perfucked"