Noun:
1. A single testicle, akin to a uniball. The result is reminiscent of the children's game: A single ball tied to a pole.
2. The term can also be used to describe someone with this condition.
Verb:
To cause someone to lose one of two testicles.
Noun:
1. Since Josh has a tetherball, his sperm count isn't as high as the average man's. But his biking has really improved.
2. "Yo Tetherball, you probably shouldn't go to the spermbank with us: You need to hold onto what you've got.... Plus, no one wants a baby with one nugget."