dickey seat
/ˈdɪki ˌsit/
noun
- A folding seat at the back of a carriage or early automobile, or a small seat attached to the back of a vehicle.
- The antique car had a dickey-seat that folded out from the trunk.
- He opened the dickey-seat for an extra passenger on the road trip.
- The children loved riding in the dickey-seat of the old convertible.
Synonyms