A tardnuckle is a hybrid of someone who acts retarded, and a knucklehead. Usually someone who enjoys playing retarded for fun and looks like a vacuous goon doing so.
Mike "I'm totally going to act full retard at the party. "
John "You would because you're such a tardnuckle."
John "You would because you're such a tardnuckle."
by A Moses August 17, 2009