BBI Share definition Flag Acronym for Big Booty Individual- A person of the female sex that has an abnormally large buttox, and has a personality similar to her thiccness. Yo this chick is a bbi, peep her gram. BBI by Joeykunz December 3, 2017 0 0 Get merch Get the BBI mug. Buy Now — $32.95 See more merch