horsecar vs streetcar

horsecar and streetcar both are nouns.

Word	Noun	Adjective	Verb	Adverb
horsecar	Yes	No	No	No
streetcar	Yes	No	No	No

As nouns, streetcar is a hypernym of horsecar; that is, streetcar is a word with a broader meaning than horsecar:

horsecar: an early form of streetcar that was drawn by horses
streetcar: a wheeled vehicle that runs on rails and is propelled by electricity

Other hypernyms of horsecar include tram, tramcar, trolley, trolley car.

horsecar (noun)	streetcar (noun)
an early form of streetcar that was drawn by horses	a wheeled vehicle that runs on rails and is propelled by electricity