A man with such a small dick that all it feels like when he fucks a woman is him fucking her with the knuckle on his fist.
HER: Enough playing around stick it in already
HIM: What you talking about Willis? It is in!
HER: I should have known you'd be a fuck knuckle.
HIM: What you talking about Willis? It is in!
HER: I should have known you'd be a fuck knuckle.
by Cereal Killer Bitch March 20, 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

(FUCK KNUCKLES) slang expression used to describe something unexpected, usually in a loud manner.****** It was just submitted and was just submitted and accepted but my phone dropped the lettet K, so it apoeared as Fuck Knucles. So sorry about that********
by Tabago's mom March 30, 2019

by CurseWordGenerator2000 January 28, 2019

by Invented that word December 10, 2024

What a fuck-knuckle.
by #CoronaTime_420_69_51 March 24, 2020

A person so dumb they can't tell the diffrence of a penis or finger and think the knuckle on a finger is the end of the dick head.
That bitch was so gross I couldn't get hard. So I fucked her with my finger and told her I have a small dick. She said the end of my head was big she is so dumb what a fuck knuckle
by Rawdog75 January 13, 2025
