What does BBS mean? BBS means "Be Back Shortly", and is generally said in a game or chat, to let others know that they may not see any comments directed to them. Generally it means that the person is going to back in a short time, however in some cases, it is used for a longer time of absence when the term "BBL" or "AFK" could have been used as well. Also known as "BRB" May also be used to refer to the Bulliten Board Service