city vs Huntsville

city and Huntsville both are nouns.

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

city (noun)	Huntsville (noun)
people living in a large densely populated municipality	a city in northern Alabama; center for space research
a large and densely populated urban area; may include several independent administrative districts
an incorporated administrative district established by state charter