An epiphany of thought. When someone suddenly has a brilliant idea.
omg, i just birthed a brain baby.
by Volcanis July 19, 2011
The result of when a man jizzes in a girl's ear
My girlfriend didn't want me to cum in her mouth, so I came in her ear. In 9 months, she'll be having a brain baby.
by wotcher now October 20, 2010