noun, plural ton·neaus, ton·neaux [tuh-nohz] /tʌˈnoʊz/.
- a rear part or compartment of an automobile body, containing seats for passengers.
- a complete automobile body having such a rear part.
- a waterproof cover, generally of canvas or vinyl, that can be fastened over the cockpit of a roadster or convertible to protect the interior.
noun plural -neaus or -neaux (-nəʊ, -nəʊz)
- Also called: tonneau cover
- a detachable cover to protect the rear part of an open car when it is not carrying passengers
- a similar cover that fits over all the passenger seats, but not the driver’s, in an open vehicle
- rare the part of an open car in which the rear passengers sit
1901 as a part of an automobile, from French tonneau, literally “cask, tun.” (see tun).