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Look up tonneau in Wiktionary, the free dictionary.
A tonneau is an area of a car or truck open at the top, when first instituted the tonneau was a pair of high-sided barrel-shaped seats, usually detachable additions to a roadster.
Tonneau may also refer to:
- Tonneau (wine barrel), oak barrels for winemaking
- Tonneau (unit), a former unit of mass in the US