Top definition
It is when you clock a muther fucker in the face while you have your middle finger extended.
Dude this chauch was talking serious trash at the club last night, so I straight up Knuckle Fucked his ass.
by Freak Sho September 25, 2010
Get the mug
Get a Knuckle Fucked mug for your mother-in-law Nathalie.