A genuinely shitty player at anything they play. The type of gamer who will talk about how high ranked he should be while struggling to get out of mediocre ranks. Someone who parses low but has an excuse for every mistake they make over and over again.
"Man, this guy sucks, what a graveboot"
"Oh yeah I'm usually way better but I'm just messing around in silver this season because I don't feel like trying" -typical graveboot response
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.