trolley vs trolley car

trolley and trolley car both are nouns.

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

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

trolley and trolley car: a wheeled vehicle that runs on rails and is propelled by electricity

Other synonyms of trolley include streetcar, tram, tramcar.

trolley (noun)	trolley car (noun)
a wheeled vehicle that runs on rails and is propelled by electricity	a wheeled vehicle that runs on rails and is propelled by electricity