BBIAB means "Be Back In A Bit", and is generally said in a game or chat, to let others know that they may not see any comments directed to them. Many times, it also means that the person is going to take a while before returning, however in some cases, it is used for a short time of absence when the term "BRB" or "BBS"could have been used as well. Also known as "AFK" or "BBL"