When ones testicles have shrunk to levels that are difficult to measure. Most often, this condition is caused by being whipped into submission and abused repeatedly by heartless a member of the opposite sex. The infected party usually dishes out all monetary earnings to help support worthless causes. In extreme cases, eunuchs have more balls than someone with nanonut syndrome.
Vito, your nuts have practically disappeared. Nanonut syndrome is recoverable, but you have to grow a sack again. You can start by donkey punching her.