From Longman Dictionary of Contemporary Englishsleeping carˈsleeping car noun [countable] TTTa railway carriage with beds for passengers to sleep in SYN sleeper
Examples from the Corpus
sleeping car• Luxury for first class travellers: a sleeping car attendant delivers hot water bottles on the London-to-Inverness Express, January 1935.• He kept getting up and going to the window to look down on his sleeping car.• It jumped in to fill a gap when InterCity ended seated accommodation on most sleeping car trains. 