Michel Delaye today asked about an explanation of OK that has been floating around for a long time. Michel wrote:
“I’ve been told an other story [about OK]: during the War between the States, OK was written for 0 (zero) K(illed)on the daily casualty report. I’d be pleased to have your opinion on this unusual explanation.”
This story is what we call a linguistic “urban myth”. It seems to make sense but has a fatal flaw: the first published instance of “OK” appeared in 1839, 22 years before the Civil War began. Moreover, words always circulate several years before they are published.
This explanation is in a class with the tale that posh oritinated from a stamp on first-class tickets from England to India and stood for “port out starboard home”. Apparently, the right side of the ship was out of the morning sun on the way to India and the left side, on the return trip. The problem with this story is that even though many such tickets have been preserved, none contain any such stamp or lettering and no other printed evidence of this abbreviation has been found.
One other linguistic myth you might encounter is the claim that the English adjective gaudy is an eponym of the Spanish architect Atoni Gaudi. Again, the problem is timing: the English adjective gaudy has been in print since 1540 and it appears in the Canterbury Tales (ca 1386) with a different meaning.
Always come to Dr. Goodword for your etymologies.