gondola car vs gondola

gondola car and gondola both are nouns.

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

As nouns, gondola car and gondola are synonyms defined as:

gondola car and gondola: a low flat-bottomed freight car with fixed sides but no roof

gondola car (noun)	gondola (noun)
a low flat-bottomed freight car with fixed sides but no roof	long narrow flat-bottomed boat propelled by sculling; traditionally used on canals of Venice
	a low flat-bottomed freight car with fixed sides but no roof
	the compartment that is suspended from an airship and that carries personnel and the cargo and the power plant