In France, a light-wheeled vehicle with square or rounded body and rear entrance.
Orig., the after part of the body with entrance at the rear (as in vehicle in def. 1); now, one with sides closing in the seat or seats and entered by a door usually at the side, also, the entire body of an automobile having such an after part.
An early style of touring car for 4 passengers in which access to the rear compartment was by a rear door. Later, when wheel bases became lengthened, doors were fitted at the sides of the tonneau; such cars became known as side entrance tonneaus. The tonneau refers to that portion of the body located aft of the front seat.