car vs lounge car

car and lounge car both are nouns.

Word	Noun	Adjective	Verb	Adverb
car	Yes	No	No	No
lounge car	Yes	No	No	No

As nouns, lounge car is a hyponym of car; that is, lounge car is a word with a more specific, narrower meaning than car:

car (noun)	lounge car (noun)
a motor vehicle with four wheels; usually propelled by an internal combustion engine	railroad car having a bar and tables and lounge chairs
a wheeled vehicle adapted to the rails of railroad
where passengers ride up and down
the compartment that is suspended from an airship and that carries personnel and the cargo and the power plant
a conveyance for passengers or freight on a cable railway