Originated in the earlyu 1940s used, by butchers to communicate with their often lonelybitches and or dawgs. The verb 'to cleap' simply means to rankleshankle an animal with such vigour or vitality that the vital organs of said animal, are sent flying out of the animal and into the mouth of any watching shoppers.
"Oh aye, pat, wants ye, t'to t'go up t'shop, and cleap a t'young, maidnely sheep? Yes, pat, i do like t'mushy peas."
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.