oh my gosh

by guess or by gosh

at random

oh dark hundred

Some unspecified hour in the early morning (implies an unpleasant time to be awake)

oh dark thirty

Some unspecified hour in the early morning (implying an unpleasant time to be awake).

oh my

oh my God

oh my goodness gracious

Oh my God.

oh well

An expression of mild disappointment or resignation: too bad; it's a pity; what can you do; it is what it is.