Combination of "Peter Out" and "Jam Tart". The name that you call someone when they peter out on a plan or party.
James: "I have to head home guys."
Bob: "You're petering out on us man?"
James: "Yeah, have to head out."
Bob: "Oh man, Peter J Tart. I can't believe you're jam tarting on us man!"
Bob: "You're petering out on us man?"
James: "Yeah, have to head out."
Bob: "Oh man, Peter J Tart. I can't believe you're jam tarting on us man!"
by Mitsuda August 9, 2007