OK

Definitions

General English

  • interjection used for answering ’yes’ to a question
  • interjection used for starting to talk about something after a pause

Computing

  • noun used as a prompt in place of ‘ready’ in some systems

Information & Library Science

  • interjection an informal word meaning ‘correct’ or ‘yes’, sometimes used as a computer prompt to ask if you want to continue

Slang

  • exclamation all right, correct. The term is no longer thought to be slang, but its origins are frequently debated by amateur and professional etymologists. The first recorded use was in the Boston Morning Post of 23 March 1839 by C. G. Greene, who used OK as a facetious abbreviation of a mis-spelled ‘Orl Korrect’. This novelty, possibly reinforced by the Scottish phrase ‘Och, aye’, which has the same meaning and an almost identical pronunciation, was imitated by other comic writers and taken as the title of a Democratic political club in 1840; this last example was also probably a pun on ‘Old Kinderhook’, the nickname of the politician Martin van Buren. The several other proposed sources for the word, including a posited cry in french au quai! (‘to or on the quayside’), are probably spurious. By the end of the 19th century OK was in use in Britain.
  • acronym forOrl Korrect

Origin & History of “OK”

Few English expressions have had so many weird and wonderful explanations offered for their origin as OK. there is still some doubt about it, but the theory now most widely accepted is that the letters stand for oll korrect, a facetious early 19th-century American phonetic spelling of all correct; and that this was reinforced by the fact that they were also coincidentally the initial letters of Old Kinderhook, the nickname of US president Martin Van Buren (who was born in Kinderhook, in New York state), which were used as a slogan in the presidential election of 1840 (a year after the first record of OK in print).
http://www.dictionarycentral.com/definition/ok.html