1717, back-formation from chaise (q.v.), wrangled into English and mistaken for a plural.
(French: "chair"), originally a closed, two-wheeled, one-passenger, one-horse carriage of French origin, adapted from the sedan chair. The carrying poles, or shafts, were attached to the horse's harness in front and fixed to the axle in back. The body of the carriage was set in front of the axle with its bottom lower than the shafts. The chaise body's position between the shafts provided stability but made side doors impossible, so that the passenger had an awkward climb over (or else had to duck under) the shafts in order to enter the carriage by a front door that opened downward. At first, the passenger drove the horse from within; later, the chaise was managed by a driver riding the horse