To turn someone's backpack inside-out and reinsert the contents back in. Usually used as a prank. Past tense: capooned
His backpack just got capooned.
I capooned his backpack.
He's going to capoon her backpack.
Also known as Nuggeting; a popular in-school form of entertainment where the "Capooner" flips the victim's back-pack inside out and puts all the books back inside.
Nick - Yo, Joe just got Capooned while he was on the lunch line.
Mike - Look, Dan just said he did it, Joe wants him to flip it back.
Nick - Dan is sayin' no, looks like there's gonna be a fight.
Mike - I got my money on Joe, what about you?
Nick - Yeah Dan doesn't stand a chance, Joe will teach him never to capoon anyone's backpack again.