OK

Noun
an endorsement; "they gave us the O.K. to go ahead"

Noun
a state in south central United States

Adjective S.
being satisfactory or in satisfactory condition; "an all-right movie"; "the passengers were shaken up but are all right"; "is everything all right?"; "everything''s fine"; "things are okay"; "dinner and the movies had been fine"; "another minute I''d have

Adverb
sentence-initial expression of agreement