town vs Portsmouth

town and Portsmouth both are nouns.

Word	Noun	Adjective	Verb	Adverb
town	Yes	No	No	No
Portsmouth	Yes	No	No	No

town (noun)	Portsmouth (noun)
the people living in a municipality smaller than a city	a port town in southeastern New Hampshire on the Atlantic Ocean
an urban area with a fixed boundary that is smaller than a city	a port city in southern England on the English Channel; Britain's major naval base
an administrative division of a county	a port city in southeastern Virginia on the Elizabeth River opposite Norfolk; naval base; shipyards