Fetish involving someone going through a woman's vagina and into the womb, usually coming back out later on. Pretty obviously restricted to cybersex and fantasy art or writing.
by Carne Largo October 15, 2003
A mysterious new enemy from Kingdom Hearts: Birth by Sleep. All we know is that they move fast, are blue, and have piercing red eyes.
"What are the Unbirth?"
by Grimrock August 03, 2008