OK1 (also o·kay / ˈōˈkā/ ) inf. • interj. used to express assent, agreement, or acceptance: OK, I'll pass on your message OK, OK, I give in. ∎ used to introduce an utterance: “OK, let's go.”• adj. satisfactory but not exceptionally or especially good: the flight was OK. ∎ (of a person) in a satisfactory physical or mental state: are you OK, Ben? ∎ permissible; allowable: I'm not sure if it's OK to say that to a teacher.• adv. in a satisfactory manner or to a satisfactory extent: the computer continues to work OK.• n. [in sing.] an authorization or approval: do you know how long it takes for those pen-pushers to give us the OK?• v. (OK's, OK'd, OK'ing) [tr.] sanction or give approval to: the governor recently OK'd the execution of a man who had committed murder.ORIGIN: mid 19th cent.: probably an abbreviation of orl korrect, humorous form of all correct, popularized as a slogan during President Van Buren's reelection campaign of 1840; his nickname Old Kinderhook (derived from his birthplace) provided the initials.OK2 • abbr. Oklahoma (in official postal use).