I'm resurrecting this thread because I'm still fascinated by this word. I've been exposed to it frequently in the last month, having gone to the national conference for architecture students. It's an incredibly commonly used word in the arch community and I'm surprised that I have yet to see it in any dictionary. I googled it and one source described it as tsuwm did, an intense final design sequence. This is not at all how I've heard it used. It's always been used in more of a preliminary, experimental context. For instance, I've heard of cities gathering together architects and planners to have a one or two day charrette to come up with an idea for a new urban plan for the city. I think the term is taking on the sense of just any intense, short term design process. I'm wondering what, if anything, the OED says about this mysterious word. A friend of mine looked it up in a French dictionary and it meant chariot. I don't see the relation.