(noun)
1. The act of using illegitimate means to gain an advantage over other people, typically for personal gain in a competitive environment, but sometimes just for the fun of it as a means to power trip. Universally considered a dick move against your fellow man.
We were playing Texas Hold 'Em and Chad took the pot when he got a royal flush because he was hiding an ace up his sleeve. He's a cheater. That's not poker, that's dirty pool.
When 2 penises are double penetrating a woman, and the bottom penis slips out. Then as he tries to re-enter, he instead pushes the testicle of the guy on top into her anus.
“Ouch, Chad. Watch what you’re doing down there. Don’t go playing dirty pool.”
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.