Endorsement; approval.

“We can start as soon as we get the OK.”

To approve.

“I don't want to OK this amount of money.”

To confirm by activating a button marked OK.

All right, permitted.

“Do you think it's OK to stay here for the night?”

Satisfactory, reasonably good; not exceptional.

“The soup was OK, but the dessert was excellent.”

In good health or a good emotional state.

“He's not feeling well now, but he should be OK after some rest.”

Satisfactorily, sufficiently well.

“The team did OK in the playoffs.”

Used to indicate acknowledgement or acceptance.

“I promise to give it back. – OK.”

Used to introduce a sentence in order to draw attention to the importance of what is being said.

“OK, I'm thinking of a number…”

Used in turn-taking, serving as a request to the speaker to grant the turn to the interrupter.

“You always do this to me! When we were at your mother’s, you said that… – OK, OK, …”