BRB is slang for "Be Right Back." This commonly used acronym is often used while texting or chatting online. However, there are also several synonyms that can be used instead of BRB. Some of the most common ones include "G2G" (got to go), "TTYL" (talk to you later), "AFK" (away from keyboard), "BBL" (be back later), and "IMK" (I'll be back). Each of these phrases is used as a replacement for BRB. It's good to know these alternatives so that you can avoid confusion and communicate clearly with others while messaging or chatting online.