brain sac

(noun) a reference to scrotum that developed due to similarities between the appearance of the scrotum and the brain (some scrotums more than others). This link is reinforced by the fact that testosterone (a hormone commonly associated with male behavior) is produced by the testicles, which are housed within the scrotum.

They cut some giblets from my brain sac, and now I can't make babies.

by GabrielSix April 13, 2005