An intellectually challenged person.
Although the term would seem self-explanatory, it has no relation to a scrotum condition whatsoever. (not even from standing waste-deep in a gelid water!!!)
In many a case, Russian private soldiers invading Czechoslovakia in 1968 were numbnuts. The hey I dont know how to work the tap I guess I will just use the force of a hammer to make the water run out of the wall ones