1) A man of the meat trade who is sly by nature.
2) A lady's man who has more than one woman on the go at the same time, but keeps this fact to himself through the cunning art of being sneaky.
1) Mr Bloggs the butcher only gave me four and a half pounds of brisket instead of five! That butcher is sneaky!
2) Ben really is a sneaky butcher; you never know where he'll put his meat!
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.