Rotterdam vs city

Rotterdam and city both are nouns.

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

Rotterdam (noun)	city (noun)
the 2nd largest city in the Netherlands; located in the western Netherlands near the North Sea	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