BRB — "be right back" (usually used in chats and on an instant messenger service).

What else could BRB stand for?

BRB is chat room talk meaning “be right back.”

What does BRB mean from a guy?

What does it mean when a guy says BRB? BRB is an abbreviation for “Be Right Back”. It means I'll be right back. It is used when chatting with someone and you need to end the chat temporarily to attend to something else.