(noun)
A black man that is really actually white on the inside.
(verb)
The act of participating in the tribal dialect and having high amounts of melanin in your skin, making you look like a dark chocolate Hershey bar of an African black but acting like a more pure, white man, kind of like Trae.
White man 1: "Man, have you noticed anything about that blacknilla man over there?"
White man 2: "Yeah, that's Trae, he always seems to act very blacknilla."
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.