When you or your partner shits on your hand while you shove your hand up their anus up to your knuckles.
by quentwestwood February 20, 2022

The crease of your pants, separating where the two balls are, stretching the sack like a frogs webbed foot.
I looked down at my boyfriends egregious frog's knuckle and told him he needs to go a size up because his nutsack was showing
by mattyctrapz December 27, 2018

by Alpha Feemale February 2, 2024

'Filth knuckle' when you're knuckle deep in pussy and the lass hasn't the best personal hygiene... when your finger(s) come up for breath you have a suspicious brown stain on the back of your knuckle(s).
I've never had such bad filth knuckle as last night... it was like I'd been eating dark chocolate with the back of my hand.
by Huw Jorgan September 12, 2016

A knuckle dripper is when, after a long, hard day of beating your meat, your volcano tries to erupt at the end of the day, and it ends up rolling down your knuckles like a tear running down your cheek.
Wife: "Honey, I thought you were gonna, like, give me a facial. Not some knuckle dripper.
Husband: "Sorry, honey, you were at work all day."
Husband: "Sorry, honey, you were at work all day."
by XDontieDankboyX November 19, 2022

by JoeyBomm July 21, 2024

Dude, Gavin just told me Katie deceided to get a little freaky and go finger to the power of knuckle on him whilst providing oral pleasure.
by Street Lethal February 19, 2011
