Herculaneum vs city

Herculaneum and city both are nouns.

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

Herculaneum (noun)	city (noun)
ancient city; now destroyed	people living in a large densely populated municipality
	a large and densely populated urban area; may include several independent administrative districts
	an incorporated administrative district established by state charter