Someone who is on the autistic spectrum and knows a lot of information about specific topics. They tend to prefer face to face interactions over text because they come across differently than they do in person. Examples of this include giving unwanted opinions to strangers online/twitter regarding science or medical care. Doesn't take kindly to being made fun of. Has nothing better to do than make this urban dictionary definition.
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.