biab Share definition Flag Acronym for "back in a bit". An alternative is bbiab. Used on chat programs, such as AIM, IRC, etc.. <Person1> Hello! <BusyPerson> Sorry, can't talk now, biab! <Person1> *grumble& biab by Talrias June 23, 2004 0 0 Get merch Get the biab mug. Buy Now — $32.95 See more merch