tramcar vs horsecar

tramcar and horsecar both are nouns.

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

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

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

tramcar (noun)	horsecar (noun)
a four-wheeled wagon that runs on tracks in a mine	an early form of streetcar that was drawn by horses
a wheeled vehicle that runs on rails and is propelled by electricity