WordNet sense 1 (a state in south central United States):

Oklahoma, Sooner State

WordNet sense 2 (an endorsement):

okay, o.k., okeh, okey

WordNet sense 3 (being satisfactory or in satisfactory condition):

fine, hunky-dory, fine, all right

WordNet sense 4 (giving satisfaction):

satisfactory

WordNet sense 5 (an expression of agreement normally occurring at the beginning of a sentence):

alright, very well