1. A mistake at a party e.g. someone stepping on someone elses foot, somebody bumping into people, somebody spilling beer everwhere, accidental cigarette burn, or when someone fumbles the pipe.
"Did you see the way they dropped me on that last kegstand? Major partyfoulers they are."
A person that will always convince you to party, especially if you're unmotivated or hungover.
Lyle: "I'm so shakey and bloated, I will never party again. I retire."
Sage: "Don't be a fag on Natturday... let's shotgun some Natty and start this game of wizard sticks."
Lyle: "You're such a partymonger! Where would I be without you? My Nattmare is over!"