Stands for Oh My Jim, after the character Jim Halpert from The Office. It can also stand for Oh My Jim, after Jim Carrey. People who use this term are well known for their extreme obsession/fandom of people/characters named Jim. They use the name Jim in place of God because they believe that Jim is more superior to God.
C - "Wow, look at that guy! He looks so cool!"
E - "OMJ! That's so cool! I totally have to go to your house and swim in it."
E - "OMJ! That's so cool! I totally have to go to your house and swim in it."
by Doctor Huddy June 05, 2009