The place where you umbilical cord used to plug in when you were a little fetus. That's how you got nutrition from Mom.
When they snipped it off, it made an
ugly scab, on your belly whuch healed and left a little knob about the size of a button. If they didn't trim it enough, it's an outie, and if they trimmed it weel it's an innie.
The belly button collects little balls of fuzz called nerds.
If you
poke somone in the belly buttton, they might laugh
like the Pillsbury dough
boy.