charrette \shuh-RET\ (noun) - 1 : A final intense effort to complete a design project. 2 : A preliminary meeting involving stakeholders (citizens, planners, designers, etc.) to brainstorm or to elicit input on a project.
"In spite of an all night charrette during which much coffee and donuts were consumed, the project was not only no closer to completion but many more flaws had made themselves evident."
From French charrette (cart), from Old French. How to get from a cart to the above mentioned senses is not clear. It's perhaps from the idea of speed when referring to wheels. Also, according to a story, professors at the Ecole de Beaux Arts in Paris collected students' drawings in a cart and the latter would often jump on the charrette to complete last-minute details.