city vs Tulsa

city and Tulsa both are nouns.

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

city (noun)	Tulsa (noun)
people living in a large densely populated municipality	a major city of northeastern Oklahoma on the Arkansas river; once known as the oil capital of the world and still heavily involved in the oil and gas industries
a large and densely populated urban area; may include several independent administrative districts
an incorporated administrative district established by state charter