You meant to search for Christmas on this site, but just like what happened to Porb, you made a typo and typed Chirstmas instead. Now you are reading this.
Antheist: I wonder what Christmas is.
*Look it up on Urban Dictionary*
*Mistype it to Chirstmas*
*See this definition*
Antheist: Lmao!
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.