interj. , informal Wow! Indication of surprise, good or bad. "Good grief," Joe cried out loud. "Is this all you will pay me for my hard work?" What a figure Melanie has, good grief! I wonder if she would be willing to go out with me.
Compare: GOODNESS GRACIOUS!, HEAVENLY DAYS!, HOLY CATS or HOLY COW or HOLY MACKEREL or HOLY MOSES. See: GOODNIGHT 2 .