Definitions by George Merriam

OMB 

(oh-em-bee) A phrase similar to OMG. Simply put it means Oh my Bieber. Usually used by a underaged teen ager who is a fan of Justin Bieber. acronym.

Bieber fan#1: OMB! Justin just made a new song.
Beber fan#2: I know, it's SO good! OMB!

OMB by George Merriam November 7, 2010