Newspeak, bureaucracies or just jargon?

Some time ago, one David Tonizzo of Toronto sounded off in a Globe and Mail letter about that city’s waste and recycling receptacles or, as he termed them, “the new street furniture.”
He wrote, “I took part in a charette to provide guidance on (this) program.”
Charette was an unfamiliar word to me, so I looked it up. The first dictionary I consulted, the American Heritage, doesn’t list this word. Neither do Oxford Canadian and Nelson. My newest dictionary, a 2006 Collins, is equally unhelpful.
Charette is in my elderly OED, of course, but that dictionary’s definition comes nowhere near Tonizzo’s use of the word. Oxford says, “The word used in the Bible of 1611 but changed in later editions to chariot. A wheeled conveyance for persons or goods. A war chariot.”
The newest edition of the OED does note the meaning found in the Globe and Mail letter. There, I discovered a charette is a workshop for designers and planners — a teamwork session in design.
Who knew?
Although charette has made it into some dictionaries, it hasn’t entered everyday vocabulary. It’s clearly an example of jargon.
And what is jargon? Most people would probably agree if told jargon is that pretentious doublespeak used by bureaucrats and politicians. And it is. But jargon is much more than that. It’s the ‘insider’ language used by any specific group — criminals, police, civil servants, computer techies, educators, the military, and the media. You name it, there’s a vocabulary attached. And, sadly, most others don’t understand that specialized vocabulary.
Newspeak: A Dictionary of Jargon, edited by Jonathon Green, uses the term “trade slang.” In my opinion, this is a perfect definition of jargon.
Charet/Charette is from Middle English, lifted from the Old Northern French word charrette, a diminutive of charre/carra (two-wheeled wagon; a vehicle). Charre is, in turn, parallel to the Old Celtic karros. This same history applies to chariot, so we can see how those first compilers of the King James Bible came to use charette.
All these early forms refer to vehicles, so we shouldn’t be surprised to learn that our word car shares this etymology.
Car is older than we might imagine and was used as early as the 16th century to refer to a wheeled vehicle. By 1697, car also meant the seven stars of the Great Bear constellation (Ursa Major, The Big Dipper).
In 1837, it referred to “vehicles designed to travel on railways.” In 1896, car was applied to the automobile.
But all these meanings refer to wheeled vehicles. How on earth did charette become “a workshop?”
That’s unclear.
Current usage of charette arose only in the mid-20th century. It possibly springs from a 19th century practice of circulating a cart among Parisian architectural students to pick up and deliver their work to exhibitions at Ecole des Beaux Arts. It’s suggested that the word used for the mode of transportation was then applied to the product transported.
This explanation, though feeble, is the best anyone has yet come up with.