Okay is a term of approval or assent, often written as OK, O.K., ok, okay, okee, or more informally as simply kay, k or kk. When used to describe the quality of a thing, it denotes acceptability. However, its usage can also be strongly approving; as with most slang, its usage is determined by context.
The word "okay" is currently the single-most-used word on Earth, owing to its common employment in a vast number of cultures and languages.
There are several theories about the origins of this word, some of them apocryphal and none of them conclusive, although the suggested origin as an initialism of oll korrect has relatively widespread support. Whatever its origin, the word spread around the world, the "okay" spelling of it first appearing in British writing in the 1860s. Spelled out in full in the 20th century, 'okay' has come to be in everyday use among English speakers, and borrowed by non-English speakers. Occasionally a humorous form okee dokee (or okey dokey) is used, as well as A-ok.
In the Choctaw language, there is a word "okeh" with the same meaning and pronunciation as American usage; Woodrow Wilson, among others, used this spelling to emphasize the Native American origins of the word. The Choctaw language was well known as a lingua franca of the frontiersmen of the early 19th Century, including eventual American Presidents Andrew Jackson and William Henry Harrison.
Allen Walker Read wrote six articles in the journal American Speech in 1963 and 1964 on the origins of the word. He dismissed the Choctaw origins as mythic folklore, emphasizing the possibility that "OK" arose as a cute abbreviation.
He believed the word to be short for any of several different spellings of "all correct", including "Oll Korrect", "Orl Korrect", and "Ole Kurreck". There was a fad in the 1830s and 1840s involving the intentional misspelling of common phrases, and referring to them by the resulting initials. These may have been influenced by the Low German phrase "Oll klor", which would have been spoken by emigrants from Northern Germany. The fad included many other briefly popular abbreviations such as OW, "oll wright" (all right) and KY, "know yuse" (no use), none of which has survived. The first recorded use of "OK" in this sense was in the Boston Morning Post on March 23, 1839, in the following passage (mostly probably written by editor Charles Gordon Greene):
The above is from the Providence Journal, the editor of which is a little too quick on the trigger, on this occasion. We said not a word about our deputation passing "through the city" of Providence.—We said our brethren were going to New York in the Richmond, and they did go, as per Post of Thursday. The "Chairman of the Committee on Charity Lecture Bells", is one of the deputation, and perhaps if he should return to Boston, via Providence, he of the Journal, and his train-band, would have his "contribution box," et ceteras, o.k.—all correct—and cause the corks to fly, like sparks, upward.
Read discounts evidence of earlier popular origins of the word; for instance, a Boston businessman used it in a daily journal in 1815, but Read argued in context it does not seem to be used in the sense of "okay, good".
Some have claimed U.S. President Andrew Jackson invented OK as an abbreviation of "Oll Korrect"; it is possible that Jackson used the term, since it was in currency towards the end of his life. Jackson may also have known the similar Choctaw word (see below).
"O.K." is the abbreviation (spelled correctly) of the Greek expression, Ola Kala (Ολα Καλά, ΟΚ) It is a standard expression in Greece that simply means: "Everything's fine". Some teachers still use it to mark good school papers with.
The abbreviation "OK" was informally used to communicate the "All's well!" (with light or other means) with shore or other ships . Also, for the Captain of a ship, hearing the Ola Kala was a quick way to take stock of a situation. OK did not however signify acquiescence to a command, as in: -"Do this!" -"OK!" The expression En Taxe, meaning "in order" would have been used in that case.
OK was also marked on shipping crates after inspection to signify that everything in them was all right. It is possible that port communities worldwide came in contact with "O.K." thusly. Throughout history, the Greek presence on the seas has been disproportionately large compared to the size of the country. The current (2006) Greek merchant fleet, for example, is larger than both US and Japanese fleets combined.
Another plausible etymology for "okay" is the suggestion that the expression may have entered North America along with African slaves many of whom arrived speaking one or more of several west African languages in which [oke] ("okay" or something close to it) was already part of the vocabulary, with a semantic scope quite close to that of "okay" in contemporary English. "Waw-kay" is an exclamation in both Bantu and Wolof dialects, "kay" being a word meaning "yes," and "waw" an emphatic; "waw-kay" is an emphatic "yes." It is observed that of all the things a newly arrived slave might be expected to utter in the presence of their English-speaking master, the single most frequent would surely be an emphatic yes. Lending credence to the African theory is the fact that a Bantu or Wolof origin is ascribed, with little or no controversy, to such common English words as "jive" ("jev") and "banana," among others. Although "okay" may have found its way into English from an African source, the similarity of the Choctaw form could have helped to solidify its use among at least some English speakers. As in the Choctaw origin theory, in this view the word "okay" was already in significant spoken use, though rarely written, when it began to acquire the several competing backronyms ("Old Kinderhook," "Oll Korrect," etc.) that have survived in print.
The hallmark of the Occitan language is oc, the medieval Occitan word for yes, as opposed to oïl, the ancestor of the modern French oui, from the langue d'oïl of Northern France.
Vulgar Latin developed different methods of signifying assent: "hoc ille" and "hoc", which became the langue d'oil and langue d'oc (or Occitan language), respectively. The subsequent development of "oïl" into "oui" can be seen in modern French, and "hoc ille" may have evolved into OK.
All of the above
It also might be that all these sources above influenced the English usage of the word.
Since the term bears resemblance to a person's initials, many proposals have been made as to who "O.K." was, and why their name would become synonymous with acceptability.
One story says it comes from a railroad freight agent, Obadiah Kelly, who initialed bills of lading, or an Indian chief Old Keokuk who wrote his initials on treaties. Another story is that it comes from boxes of Orrins-Kendall crackers which were popular with Union troops during the US Civil War. Some say the term comes from a German businessman Otto Kaiser who put his initials on goods he had inspected. A related version ascribes it to a worker named Otto Kruger or Oskar Krause at a Ford plant in Michigan, who would inspect each car coming off the assembly line and chalk his initials on the front windshield if it was "OK".
According to the History Channel documentary, "Tune In", O.K. came from the 8th President of the United States, Martin Van Buren. Whenever Martin would sign off on something, he used the initials of his nickname "Old Kinderhook". Martin Van Buren was born in Kinderhook, NY and thus whenever he would approve of something - he would sign off, O.K.
An alleged meaning found in the popular game, Trivial Pursuit, says Andrew Jackson, one of the founders of the Democratic Party, and the seventh President of the United States, when asked about his usage of the two-letter acronym on bills, responded that OK stood for "oll korrect," a phonetic misspelling of "all correct." The likelihood of this story is supported by the fact that Andrew Jackson had a reputation as a good soldier and frontiersman, but not as of a scholar.
Another possible origin for the term "OK" comes from French fishermen, sometimes said to be based in New Orleans. When the fishermen came back from their trips and were approaching the harbour, when asked by the harbourmaster where to tie up their boats, the captain would shout "au quai", meaning "to the quay". Later, when asked how their trip went, in the local taverns etc., they would simply reply "au quai", which would indicate that their ship had been tied up to the quay to unload a lot of fish. The phrase "au quai" became synonymous with success and integrated local slang.
The term OK has also been used in an English will and testament from 1565. It is possible that this usage originates from "oak" - the tree from which ships were constructed in the British Navy. The actor David Garrick (1717-1779) wrote the Royal Navy's song "Heart of Oak", a patriotic song celebrating naval victories of the Seven Years' War (1756-1763). In Britain oak wood is a symbol of solid dependable construction. Thus it is possible to see how establishing the reliability of the vessel might involve asking if it was "oak-a?" In 2000 the First Sea Lord, Admiral Sir Michael Boyce said, in the Royal Navy's "Navy News": "It is no exaggeration to say that the reputation of the Royal Navy is founded on British oak."
Typesetters, Harvests, the Finns, the Scots or the French?
The term OK was also used by typesetters and people working in the publishing business. A manuscript that didn't need any changes or corrections would be marked "O.K." for Ohne Korrektur (German for "No changes"). Another story is that it comes from the British English word hoacky (the last load of the harvest). Or the Finnish word Oikein (that's right). Or the Scottish expression och aye. Or the French aux Cayes or au quai.
Another version is that the term was used by U.S. military during the U.S. civil war to state that there were zero casualties or zero killed ("0K"), hence 0.K., at a particular battle site.