Its a derogatory term used to describe that un which is attempted to be explained yet is unexplainable, therefore such concept is, was, and always will be such unless, except in the possible yet unlikely event of change of manner in form used as of by targetindividual applied to that of other means and/or fashions of original constructed inquiry.
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.