abbreviation of the phrase "oh my good god!"
A more intelligent version of the overated and highly irritating "omg". The exclamation is vital, it must not be omitted as it implies enthusiasm,excitment, and sheer horror. If you dont include the exclamation mark the green man will eat you. yeah, and im not even jokin' you.
used often in geek conversation.
"OMG-G! I threw a raisin at someone and a magical herron counter-attacked me"
Stacey: "Sarah and Rachel are friends with the green man"
Graham: "OMG-G! you had better be jokin' me."