A dutch word. Literal translation: vagina bag.
Used to describe someone who does everything in his power to annoy/piss off his friends. Common kutzak activities are: wet wilies, bangcocks, nipple cripples and spitting in your beer.
A true kutzak enjoys nothing more than humiliating you in front of other people/girls you are trying to impress.
Mitch: Yesterday I hit Kevin in the balls, just for fun. He was almost crying.
Frank: Dude, you're such a kutzak