OK

from The American Heritage® Dictionary of the English Language, 5th Edition.

• abbreviation Oklahoma
• adjective Satisfactory or agreeable; acceptable.
• adjective Correct.
• adjective Barely satisfactory; mediocre.
• adjective In proper or satisfactory operational or working order.
• adjective Uninjured or not seriously injured.
• adjective Fairly healthy.
• noun Approval; agreement.
• adverb Fine; well enough; adequately.
• interjection Used to express approval or agreement.
• transitive verb To approve of or agree to; authorize.

from The Century Dictionary.

• noun A Middle English variant of oak.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• proper noun Acronym of Oklahoma, a state of the United States of America.
• noun endorsement; approval
• verb To approve.
• verb computing To confirm by activating a button marked OK.
• adjective all right, permitted
• adjective satisfactory, reasonably good; not exceptional
• adjective in good health or a good emotional state
• adverb satisfactorily, sufficiently well
• interjection Used to indicate acknowledgement or acceptance.
• interjection An utterance expressing exasperation, similar to "all right!"
• interjection Used to introduce a sentence in order to draw attention to the importance of what is being said.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a state in south central United States
• adverb an expression of agreement normally occurring at the beginning of a sentence
• adjective being satisfactory or in satisfactory condition
• noun an endorsement
• verb give sanction to
• noun an endorsement
• adverb in a satisfactory or adequate manner
• adjective being satisfactory or in satisfactory condition