An exclamation of excitement, surprise, shock etc.; oh my God
"Oh my god! OMG, you won the lottery?"
Initialism of Object Management Group.
"The OMG is developing new standards to improve interoperability between different software systems."
Alternative form of OMG:
"She typed omg in her text message to express shock at the news."
Oh my God.
"Oh my God, I just dropped my phone! omg"
OMG is an abbreviation for "oh my God" that entered English usage as a way to express shock while avoiding direct profanity through minced oaths. Its earliest recorded use in 1980 also played on the name of the Order of St Michael and St George, creating a pun before becoming a standard internet acronym.