A couchette is a bed on a train or a boat which is folded against the wall or used as a seat during the day.
[mainly British]
couchette in British English
(kuːˈʃɛt)
noun
a bed in a railway carriage, esp one converted from seats
Word origin
C20: from French, diminutive of couche bed
couchette in American English
(kuˈʃɛt)
noun
an inexpensive berth on a European train, consisting of a shelflike bed that folds down to allow passengers to sleep in their clothes: there are usually four couchettes in a first-class compartment and six in a second-class compartment