Definition of rumble seat in US English:

rumble seat


North American
  • An uncovered folding seat in the rear of an automobile.

    • ‘In summer on nice days, I was allowed to ride in the car's rumble seat.’
    • ‘At the auto auction today there was a 1969 Mustang with a rumble seat which supposedly was a rare pseudo-factory option.’
    • ‘In one scene, Buster is forced to accept a ride from his rival, and he has to sit in the open rumble seat while Sally sits with the rival in the front.’


rumble seat

/ˈrəmbəl ˌsēt/