found: Cambridge dictionary online, January 11, 2021:(Okay; variants: OK; O.K.; English word that is used in a variety of grammatical ways, including as an exclamation, noun, adverb, adjective, and discourse marker; there are a variety of the theories of the origin of the word, including: newspaper language use in Boston in 1830s; the abbreviation of Presidential candidate Van Buren in the 1840 race, ("Old Kinderhook", named for his place of origin); Choctaw language word borrowed into English; West Africa, along with others; used as a loan word in other languages)
