city vs Mombasa

city and Mombasa both are nouns.

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

city (noun)	Mombasa (noun)
people living in a large densely populated municipality	a port city in southern Kenya on a coral island in a bay of the Indian Ocean
a large and densely populated urban area; may include several independent administrative districts
an incorporated administrative district established by state charter