Here's a quiz: let's say you're setting off to see the world and aside from please and thank you in a smattering of languages you pretty much only know English. What is the one word that most of the people you encounter will also know? That's right. It's OK . Yep. It's very probably the most widely recognized word in the world. And its origin story is literally a joke. The definitive text on the subject is by professor Allan Metcalf, whose OK: The Improbable Story of America's Greatest Word , based on the research of historian Allen Walker Read, was published in 2010. Metcalf traces the word's birth to a bit of jocular text in an 1839 article in the Boston Morning Post —a little jab from one newspaper editor to another, suggesting that his cohort in Providence, Rhode Island, should sponsor a party for some boisterous Boston lads who might be stopping by his town: ... he of the [Providence] Journal, and his train -band, would have the 'contributions box,' et ceteras, o.k.…