Simply put it is the male equivalent of a woman's camel toe. Usually caused by the seam of tight but thin leg wear such as spandex, the testicles and penis form two bulges on opposite sides of the seem that vaguely resembles the hoof, or "knuckle" of a moose. hence "Moose-knuckle"
Jon didn't wear underwear under his skintight Peterpan costume, and everyone could see that he had a moose-knuckle.
An intensified camel-toe or kuder-cleavage.
Damn girl! Your kuder must be hungry 'cause you got moose-knuckle!
Large, Defined outline of the male/female package.
"Hey, you walkin, trim up that moose-knuckle!"
black box sith twat black beaver punani African vagina, opposite of camel-toe.
Like throwing a hotdog down a hallway, Shaniquas moose-knuckle was a roaring gaping chasm.