OK

abbreviation: Oklahoma (ConUS south central state)
Found on http://www.encyclo.co.uk/local/20021

OK

abbreviation: we agree, correct
Found on http://www.encyclo.co.uk/local/20021

Ok

OK was slang and is now colloquial English for all right, correct.
Found on http://www.probertencyclopaedia.com/browse/ZO.HTM

Ok

OK was slang and is now colloquial English for all right, correct.
Found on http://www.probertencyclopaedia.com/browse/ZO.HTM

OK

Old Kingdom
Found on http://www.reshafim.org.il/ad/egypt/glossary.htm

OK

All Correct
Found on http://www.netlingo.com/acronyms.php

ok

okay
Found on http://www.noslang.com/dictionary/o/
No exact match found