The navel - what do you call yours?

Pippic is the Yiddish words and it is loads of fun to say. I had surgery on my intestine and ended up with many pippics. My surgeon cut vertically and split the one I had into two. Pippics can be used to smuggle things like diamonds through customs.

Bellybutton/belly button in most informal situations, unless I wanted to refer to the type (innie).