Knuckling 

The act of stimulating the clitoris by vigorously rubbing ones knuckles back and forth in a sawing motion.

Will walks in on Kraig and Felicity in bed together , and Kraig is violently rubbing his knuckles on her pussy.
Will: What the fuck are you doing to her ?
Kraig: I'm knuckling her! I'm getting her inflamed!
Will: Dude, just fuck her already...
Felicity: He won't fuck me until I officially go out with him.
Will facepalms, and pukes a little in his mouth.

Knuckling by Anorak79 June 5, 2018

Knuckling 

Knuckling is the act of 2 bros fist bumping eachother. As the two bros fist bump eachother, a third bro proceeds to slide his dick between the other bros touching knuckles. He then proceeds to fuck their knuckles.

Ben: Are colin and adam knuckling with that guy over there?
Sean: Yeah that dudes dick is gonna be super sore wow.

Knuckling by Zsean April 24, 2018

knuckling 

insertion of one's fingers in another's anus past the middle knuckle

She said that she had never done any anal sex. But when I was knuckling her, I knew that she was lying.

knuckling by Gatz, Stewart January 20, 2011

Knuckling 

That act of pleasuring a woman by making a fist and using ones knuckles in a sawing motion to stimulate the clitoris.

While laying naked together in the hotel bed, he applied aggressive knuckling until she was inflamed with passion.

Knuckling by Anorak79 May 29, 2018

Knuckling 

The act on which yo u make all of your fingers into knuckles and start fisting a girl

Adam- Hey did you see Stephen knuckling that girl last night

Tyler- Yea it was weird

Knuckling by Spanishpersonthatsnotspanish April 25, 2019

Knuckling one off 

When an fat dumpy lesbian beats herself off and since she's so fat she aggressively rubs her knuckles on her puss to get off

Patti couldn't get the job done with her dildo so she ended up knuckling one off on that big fat pussy

Knuckling one off by Bigdickballer420 July 25, 2017

knuckling up

major shrinkage of a man's penis to the size of a finger between two knuckles

Wow it's cold out, I can barely see my dick, it must be knuckling up.

I don't have a micropenis, it's just knuckling up!

knuckling up by Nasbaby December 17, 2010