A well-placed and extremely hard blow to the testicles. Done correctly, a nutbuster will incapacitate even the strongest man for several minutes. Best results are usually achieved with a kick, using the laces of any sturdy shoe. Other methods of nutbuster delivery include a baseball on the end of a rope, knees, or even a strong punch.
1: Any person who, in the course of giving a handjob, painfully and with great force slams into your balls on the downstroke.
2: Any person who likes and asks for the aforementioned act to be performed on them.
Dude, this total betty slid her hand down my pants at the lake last night, but when she started torquin' it, she kept slamming into my balls! Hella bad nutputter!
I went with Tom to that new bar down the street; little did I know it was an S&M joint, and he was an undercover nutputter!