city vs Pergamon

city and Pergamon both are nouns.

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

city (noun)	Pergamon (noun)
people living in a large densely populated municipality	an ancient Greek city located in the western part of what is now modern Turkey; the technique of preparing sheepskins as parchment was developed here
a large and densely populated urban area; may include several independent administrative districts
an incorporated administrative district established by state charter