Something really Hip as in Good Excellent. Sammy Davis Jr.used it constantly in his stage act. Also a Sandwich in the Philly area. Wild Rock and Roll disc jockey TheMojoMan used it at every radio station he worked thru out the 60's 70's and 80's
Man,That DeLorean he bought is a Real Mammy Jammer. Or as TheMojoMan would intro "Land of a 1000 dances" by Wilson Pickett or "Born to be Wild" by Steppenwolf
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.