n. slang 1. When a man pulls his ball sack and one nut out of his unzipped pants, making sure to sqeeze the skin behind the nut to it's bulbous glory. Said nut knuckle is usually pulled out to an unsuspecting participation as a humiliating joke.
Hey mike look at my finger I think i cut it. *pulls out the nut knuckle as mike turns to look*
*mike sees the knuckle and is in stuper*
Fuck off you nut knuckler!