Remnant undeveloped natal vagina left from the pre-hormonal sex-change surge in the uterus, that decides if the baby is either a boy or a girl in the womb.
"You see that guy over there?"
"You mean the one with the hand puppet?"
"Yeah, the one talking jibberish to the hand puppet."
"The one about to fall into the manhole?
"Yeah, him. He's a mishuginah."