To snort a small amount of cocaine from the creases of your knuckle. Usually the most discreet way to snort in public (club, party, street) so that no one will suspect anything.
Ben: Did you see that chick knuckle bump?
Tice: I sure did.
When smash a girl's giner with your knuckles and they shatter like butter you get a knuckle hucker.
Last night me and my sister got into a fight and I broke my knuckle hucker.
Toe knuckles
The joint in between your toes that when you drop something on them you feel like you just got a TOE cut off
Girl:*drops something on toeknuckles*
Girl: OWW MY TOE KNUCKLES!!!
Extending one's finger and ramming said digit into the anus until the knuckle reaches the rectum.
Nothing beats reruns of "Welcome Back Kotter" and gettin' the ole' Knuckle Sludge.
A early meme of 2018, of a weird model of Knuckles in the popular VR game VRChat asking other people of they know the way. This meme quickly spread fast and with that the meme died. Many people still use the meme today despite it's zombie-like status as a dead meme.
Person: I love Ugandan Knuckles!
Other person: I think it's meh.
when you shove your fist in someones anal cavity for sexual pleasure.
WOW! I got poopy knuckles from that skank