city in Ohio, U.S., laid out 1796 by Gen. Moses Cleaveland (1754-1806) and later named for him. His descendants included U.S. President Grover Cleveland (1837-1908). The family name (attested from 12c.) is from one of several place names in England based on Middle English cleove, a variant of cliff.
by 1953, name for human anti-coagulant use of the rat poison warfarin sodium, abstracted from the chemical name, 3-(α-acetonylbenzyl)-4-hydroxycoumarin; earlier known as Dicoumarol, it attained publicity when it was used in 1955 to treat U.S. President Dwight Eisenhower after a heart attack. Coumarin as the name of an aromatic crystalline substance is by 1830 in English, from French coumarine, from coumarou, the native name in Guyana of the tonka or tonquin bean, one source of the substance.
colloquial for "signature," 1903 (sometimes, through some unexplainable error, John Henry), from the Boston merchant and rebel (1736-1793), signer of the U.S. Declaration of Independence. The extended sense is from his signing that dangerous document first or most flamboyantly.
John Hancock, president of Congress, was the first to sign the Declaration of Independence, writing his name in large, plain letters, and saying: "There; John Bull can read my name without spectacles. Now let him double the price on my head, for this is my defiance." [Hélène Adeline Guerber, "The Story of the Thirteen Colonies," New York, 1898]
The family name is attested from 1276 in Yorkshire, a diminutive (see cock (n.1)) of Hann, a very common given name in 13c. Yorkshire as a pet form of Henry or John.
"all right, correct," 1839, only survivor of a slang fad in Boston and New York c. 1838-9 for abbreviations of common phrases with deliberate, jocular misspellings (such as 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 spelling 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, "endorsement, approval, authorization" (especially as indicated by the letters O.K.); the verb, "to approve, agree to, sanction," is by 1888. Okey-doke is student slang first attested 1932.