Generally in referance to "booty." Meaning to have a big ol' chunky, I need to be in a ludacris video and shake it, slab of meat on your backside. Though, as it is often said in the context of "clowning," the word can be iether positive or negative.
Dawwwwmmmm! Look at that ha-bunk-a-dunk booty. She look like missy elliot after eating a chubby midget.
It is said of the situation where a person has the bad luck to make contact with his testicles against an undefined surface or object, intentioned or not.
Given the nature of the word, it is more appropriate to design cases where the interaction is made with a moving object, for example, a ball.
Although it is extremely painful for the victim, it tends to be considerably funny to people who witness it.
Today in the baseball game the pitcher took a nutshot; the baseball hit him in the nuts.
Man, I just watched the funniest nutshot video ever.