1. People who you have had some kind of interaction with that have come and gone from the scope of being regularly in touch with or in touch with at all.
2. Persons who have briefly impacted you in some way and are no longer around.
3. Persons who have impacted you in a good way but are no longer around because they have continued on a path that is separate from yours. The split is usually on good terms, but you probably won't see or hear from these people again.
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.