Синоним oh my god! "Oh my god" is the standard phrase. "Oh my gosh" tends to be used by people who don't want to use the word "God", especially since there are people who believe saying the word God needlessly in such contexts is "saying the Lord's name in vain." "Oh my goddess" - never heard this before, but it's probably just making fun of the term above. |They all mean the same thing but "oh my gosh" and "oh my goodness" are ways to say "oh my God" without using God's name in vain, which is considered a sin in Christianity. But nowadays most people, including Christians, just say, "Oh my God!" anyway.|I think what you mean is "oh my goodness". That is a very polite expression.