Origin of OK

initials of a facetious folk phonetic spelling, e.g., oll or orl korrect representing all correct, first attested in Boston, Massachusetts, in 1839, then used in 1840 by Democrat partisans of Martin Van Buren during his election campaign, who allegedly named their organization, the O.K. Club, in allusion to the initials of Old Kinderhook, Van Buren's nickname, derived from his birthplace Kinderhook, New York

Usage note

Few Americanisms have been more successful than ok, which survived the political campaign of 1840 that fostered it, quickly lost its political significance, and went on to develop use as a verb, adverb, noun, and interjection. The expression was well known in England by the 1880s. Today ok has achieved worldwide recognition and use. It occurs in all but the most formal speech and writing.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for o.k.

O.K.

sentence substitute

an expression of approval, agreement, etc

adjective, adverb (usually postpositive)

in good or satisfactory condition
permissableis it O.K. if I go home now?
acceptable but not outstandingthe party was O.K.

verb O.K.s, O.K.ing (ˌəʊˈkeɪɪŋ) or O.K.ed (ˌəʊˈkeɪd)

(tr) to approve or endorse

noun plural O.K.s

approval or agreement
Also: OK, o.k., okay

Word Origin for O.K.

C19: perhaps from o (ll) k (orrect), jocular alteration of all correct

OK

abbreviation for

Oklahoma
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for o.k.

OK

1839, only survivor of a slang fad in Boston and New York c.1838-9 for abbreviations of common phrases with deliberate, jocular misspellings (e.g. K.G. for "no go," as if spelled "know go;" N.C. for "'nuff ced;" K.Y. for "know yuse"). In the case of O.K., the abbreviation is of "oll korrect."

Probably further popularized by use as an election slogan by the O.K. Club, New York boosters of Democratic president Martin Van Buren's 1840 re-election bid, in allusion to his nickname Old Kinderhook, from his birth in the N.Y. village of Kinderhook. Van Buren lost, the word stuck, in part because it filled a need for a quick way to write an approval on a document, bill, etc. Spelled out as okeh, 1919, by Woodrow Wilson, on assumption that it represented Choctaw okeh "it is so" (a theory which lacks historical documentation); this was ousted quickly by okay after the appearance of that form in 1929. Greek immigrants to America who returned home early 20c. having picked up U.S. speech mannerisms were known in Greece as okay-boys, among other things.

The noun is first attested 1841; the verb 1888. Okey-doke is student slang first attested 1932.

Online Etymology Dictionary, © 2010 Douglas Harper