A tinkering saloon style player piano, in true Wild West style.
Usually accomplanied by double hinged swinging doors, a bartender cleaning shotglasses with a dirty rag and busty whores in flouncing skirts and ankleboots.
Commonly known to be rudely interrupted by a 10 step & turn pistol-duel.
1. Gather 'round the pianner and play us a tune, Wheezy Joe.
2. Clarence, get off that pianner you're knockin' the glasses everywhere!
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.