Limerick vs metropolis

Limerick and metropolis both are nouns.

Word	Noun	Adjective	Verb	Adverb
Limerick	Yes	No	No	No
metropolis	Yes	No	No	No

Limerick (noun)	metropolis (noun)
port city in southwestern Ireland	people living in a large densely populated municipality
	a large and densely populated urban area; may include several independent administrative districts