oh¹ / ō/ • interj. used to express a range of emotions including surprise, anger, disappointment, or joy, or when reacting to something that has just been said: “Oh no,” said Daisy, appalled | Me? Oh, I'm fine | oh, shut up.PHRASES: oh boy used to express surprise or excitement.oh well used to express resignation: oh well, please yourself.oh yeah? used to express disbelief. ∎  used to express a threatening or taunting reaction.oh² • n. variant spelling of O¹ (sense 2).

OH • abbr. Ohio (in official postal use).

oh XVI. var. of O, formerly used in positions where O is now more usual, now chiefly as an excl. of pain, terror, surprise, or disapproval. — F. oh, L. ōh.