Definitions
American Heritage® Dictionary of the English Language, Fourth Edition
- n. Approval; agreement: Get your supervisor's OK before taking a day off.
- adj. Agreeable; acceptable: Was everything OK with your stay?
- adj. Satisfactory; good: an OK fellow.
- adj. Not excellent and not poor; mediocre: made an OK presentation.
- adj. In proper or satisfactory operational or working order: Is the battery OK?
- adj. Correct: That answer is OK.
- adj. Uninjured; safe: The skier fell but was OK.
- adj. Fairly healthy; well: Thanks to the medicine, the patient was OK.
- adv. Fine; well enough; adequately: a television that works OK despite its age.
- interj. Used to express approval or agreement.
- v. To approve of or agree to; authorize.
- abbr. Oklahoma.
Century Dictionary and Cyclopedia
- n. A Middle English variant of oak.
Wiktionary
- n. endorsement; approval
- v. To approve.
- v. To confirm by activating a button marked OK.
- adj. all right, permitted
- adj. satisfactory, reasonably good; not exceptional
- adj. in good health or a good emotional state
- adv. satisfactorily, sufficiently well
- interj. Used to indicate acknowledgement or acceptance.
- interj. An utterance expressing exasperation, similar to "all right!"
- interj. Used to introduce a sentence in order to draw attention to the importance of what is being said.
- interj. OK; acceptable; passed
- n. acronym of ,, a state of the United States of America.
- n. endorsement; approval
- v. To approve.
- v. To confirm by activating a button marked OK.
- adj. all right, permitted
- adj. satisfactory, reasonably good; not exceptional
- adj. in good health or a good emotional state
- adv. satisfactorily, sufficiently well
- interj. Used to indicate acknowledgement or acceptance.
- interj. An utterance expressing exasperation, similar to "all right!"
- interj. Used to introduce a sentence in order to draw attention to the importance of what is being said.
- interj. OK; acceptable; passed
- n. acronym of ,, a state of the United States of America.
WordNet 3.0
- v. give sanction to
- n. an endorsement
- adv. in a satisfactory or adequate manner
- adj. being satisfactory or in satisfactory condition
- n. a state in south central United States
- adv. an expression of agreement normally occurring at the beginning of a sentence
- adj. being satisfactory or in satisfactory condition
- n. an endorsement
Etymologies
- Abbreviation of oll korrect, slang respelling of all correct.
Examples
“Journal in 1839, at about the same time the term OK appeared: “That lawyer has been trying to spread the wool over your eyes.””
Simon & Schuster: The Right Word in the Right Place at the Right Time
“The thing is, OK translates as "OK" into pretty much every language I know of.”
“A senator in OK is holding up the Veterans bill; this happens to be a republican.”
“Dresses and trousers by Italian Daniela Gregis (under the label OK*AM) hang on the walls like paintings.”
“If you say the word 'OK,' I will take that as a sign you want me back in the lineup.”
“Today in 1839, the expression "OK" was first used in print.”
“So how did the word "OK" conquer the world, asks Allan Metcalf. ...”
“So how did the word "OK" conquer the world, asks Allan Metcalf.”
“After all, no one would dare discriminate against Protestant Christianity in OK, so the only religions that had their rights removed were Catholics, Jews, Wiccans, etc.”
“Very few countries do more than the US. gary in OK”
Lists
These user-created lists contain the word ‘OK’.

Prolagus I'm afraid this might not be the actual etymology, capco. In the "etymologies" section of this page you can find a more documented one. See also here for a list of suggested etymologies, with references. Nov 14, 2009
capco OK or Okay: (informal). Interjection indicating agreement to approval of what
Somebody said or done, also indicating that something is finished, and
No further action is to be taken.
Origin: O. for Optimum (Latin) the best or the most favorable. And,
K. (Chem.). A Symbol for equilibrium constant; the state reached
In a reversible reaction velocities in the two opposing directions
Are equal, so that the system has no further tendency to change.
(Chambers Science and Technology Dictionary).
The O. and the K. were used after double checking a formula, or a product, in order to indicate that it has passed. After the first test the O. For Optimum, was used to indicate that the formula passed. Then the K. was shown indicating ( for no further action is needed) Therefore when the symbol (OK) appeared in front of a formula it indicated that it has been double checked, and it is passed.
Nov 14, 2009