public square vs city

public square and city both are nouns.

Word	Noun	Adjective	Verb	Adverb
public square	Yes	No	No	No
city	Yes	No	No	No

public square (noun)	city (noun)
a place of assembly for the people in ancient Greece	people living in a large densely populated municipality
an open area at the meeting of two or more streets	a large and densely populated urban area; may include several independent administrative districts
	an incorporated administrative district established by state charter