Belly Boob Share definition Flag When someone has a rather large stomach, with an outie belly button, making them appear to have one large belly boob. Damn, did you see that chick? She had three boobs!Naw man, that was just her belly boob. Belly Boob by Dushawn Mandic June 30, 2009 0 0 Get merch Get the Belly Boob mug. Buy Now — $32.95 See more merch