Brb2 is the term that is typed to a friend whist chatting on an instant messenger or chatroom. Brb2 - as opposed to Brb1/Brb - means that you need to leave the conversation for a while but not because of a task that must be completed, but because of a parent or guardian walking into the room.
Basically, if someone is on ICQ looking for a hot date, and you mum walks in, instead of saying BRB (to which the other person might think you just left the conversation and then leave themselves) you say BRB2 to state that you have not left, but are waiting for someone in the room to leave before you can start chatting with them again.

Example one:
Woman: asl?
Man: 25/m/Living by myself in England
Woman: That sounds sexy, you really live away from your parents?
Man: Yeah - They live in America
Woman: Thats so hot.
Man: Crap my mum, BRB2
Moderator: LOLZUFAIL!
by WhatsherfaceBBQ July 14, 2009
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