Kindergarten Dick

Refers to a randomly occuring "small penis" situation, where the individual's member isn't usually an inch or two, but becomes as such for a time, like when someone drinks too much and their penis shrinks to nothing, but the head and minimal shaft.

"He drank so much, that his KD shriveled to match a half roll of coins!

"Yeah, he had the worst case of KINDERGARTEN DICK I've ever seen!"