city vs Portsmouth

city and Portsmouth both are nouns.

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

city (noun)	Portsmouth (noun)
people living in a large densely populated municipality	a port town in southeastern New Hampshire on the Atlantic Ocean
a large and densely populated urban area; may include several independent administrative districts	a port city in southern England on the English Channel; Britain's major naval base
an incorporated administrative district established by state charter	a port city in southeastern Virginia on the Elizabeth River opposite Norfolk; naval base; shipyards