plural of monkey brain: a green fruit which is wrinkly like a brain, about the size of a monkey's. Semi-common in Cincinnati (I know this because it’s where I’m from; they may be common elsewhere, as well, though I ’mnot aware’f where).
The official\technical\scientfic\actual\real\true term/name for it.. I don't know.
Getting hit in the head by a monkey brain ain’t as severe as gettin‘ hit by a base-ball, but it still hurts.
Me and my friends, when we were young, liked to roll monkey brains down our streets in the ’hood.