brownstone vs town house

brownstone and town house both are nouns.

Word	Noun	Adjective	Verb	Adverb
brownstone	Yes	No	No	No
town house	Yes	No	No	No

As nouns, town house is a hypernym of brownstone; that is, town house is a word with a broader meaning than brownstone:

brownstone: a row house built of brownstone; reddish brown in color
town house: a house that is one of a row of identical houses situated side by side and sharing common walls

Other hypernyms of brownstone include row house.

brownstone (noun)	town house (noun)
a row house built of brownstone; reddish brown in color	a house that is one of a row of identical houses situated side by side and sharing common walls
a reddish brown sandstone; used in buildings