Philadelphia vs city

Philadelphia and city both are nouns.

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

Philadelphia (noun)	city (noun)
the largest city in Pennsylvania; located in the southeastern part of the state on the Delaware river; site of Independence Hall where the Declaration of Independence and the Constitution were signed; site of the University of Pennsylvania	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