During a television broadcast of a movie, when a character tries to display the middle finger, the finger is cutoff because of censorship. This results in what appears to be the character showing his/her knuckles only. Considered an insult in many parts of a certain part of a certain place of certain countries. Also known as giving knuckles or showing the knuckles.
When watching 8 Mile on VH1, Eminem can be seen giving the knuckles numerous times throughout the movie.
Person 1: Yo, homeboy juss' foun' out dat hims friend was dippin' in him's mayonnaise!
Person 2: Oh snap, he juss' gave him knuckles!
Person 1: Yeah, I would too if someone was dippin' in mah mayonnaise. Bish, gitcho' own damn mayonnaise!