innie

Noun

 * 1)  Anything concave; especially:
 * 2)  A navel that is formed of a hollow in the abdomen (as opposed to one that protrudes from the abdomen).
 * 3)  A vulva with inner labia minora.
 * 4)  A vulva seen as an inverted version of a penis.
 * 5) An introvert.