look up any word, like the eiffel tower:
 
8.
A hand gesture characterized by an individual forming a closed fist with one hand and extending the index finger to the proximal interphalangeal joint only. The joint should be flexed so the distal phalange points inward toward the palm.

The gesture is executed when two participants each form this fist and lightly tap their PIP joints together.

Often initiated by one person doing or saying something really cool and the other person recognizing and respecting that action by holding up their fist as described above and saying "knuck".
Bree: Oh boy, Daddy that was the sweetest dickin' that anyone's ever given me!

Travis: KNUCK.
by Honey Bree July 22, 2010
 
9.
The action of touching two knuckles..basically a sign of coolness. Also can be used in place of 'the Eff word' :p
Knuck my life, man!

*Walking past friend* KNUCKS! *touch knuckles together*
by Alyssa Knucker November 04, 2009
 
10.
someone with big knuckles.

someone is a good fighter.
ay yo dat boy got some big knucks.

dat kid can move his knucks.
by $knucks$ $bux$ July 02, 2009
 
11.
An abbreviation of "knuckle children", which is a colloquialism for semen expelled during masturbation.
Oh man, that chick was hot. When I get home I'm gonna have to crank out a few knucks.
by defaultuser1 April 26, 2011
 
12.
Short for "knuckles".
"I'm buyin' me some brass knucks."
by Dave January 15, 2004
 
13.
my girlfriends feet are so caloused from wearing high heels, she has three extra sets of toe knuckles.
damn babe, you really need to get those extra knucks ground off!
by horsesass March 14, 2010
 
14.
Some blown out pussy lips that look like a pair of Chuck Norris' knuckles
After I got done beatin' cakes you should've seen the knucks on that broadley.
by Big Bizniz March 15, 2008