Noun. One of two forces that cause breasts to slowly sag towards the floor. Along with gravity, the force of grabity causes a constant pulling, rubbing, tugging and stretching of the breasts. The force is propotional to the sensitivity of the breasts and the attractiveness of their owner and increases exponentially in the presence of horny, attractive men.
If it weren't for the force of grabity I'd still have a "B" cup.
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.