by #CoronaTime_420_69_51 March 25, 2020
to go knuckle deep into the anal regions of the other gender while your other knuckle is 5 inches deep in their other genital region.
you have just been fuck knuckled by him
by Gizard XD March 1, 2017
Dude this chauch was talking serious trash at the club last night, so I straight up Knuckle Fucked his ass.
by Freak Sho September 26, 2010
When hitting a large jump (booter) mainly on skis there is a roller or knuckle that the jump sits on. If you hit that jump and land a little short that is called a case. But if you case the jump so hard that you are ejected from your skis and you thrust your body so hard against the landing that is called a Knuckle Fuck because you are fucking the knuckle.
by AbsorbedSpoon3 July 6, 2019