For other uses, see OK and Okay . Okay is an informal term of approval, assent, or acknowledgment. It is often written as OK or sometimes deceiving form of O.K., which would suggest it is two words but it is not. (See also A-ok.) When used to describe the quality of a thing, it denotes being fit for purpose ("this is okay to send out") or of a quality which is acceptable but not great ("the food was okay"). When used in dialogue, it can denote compliance ("okay, I'll do that"), agreement ("okay, that's good"), a wish to defuse a situation or calm someone ("okay, it's not that bad"), or even formal approval ("you're okay to do that"). As with most slang, its meaning is determined by context. The origins of okay are not known with certainty, and have been the subject of much discussion and academic interest over the years. Earliest documented examples Disprov