Gulf of Naples vs Italian Republic

Gulf of Naples and Italian Republic both are nouns.

Word	Noun	Adjective	Verb	Adverb
Gulf of Naples	Yes	No	No	No
Italian Republic	Yes	No	No	No

Gulf of Naples (noun)	Italian Republic (noun)
an arm of the Tyrrhenian Sea at Naples	a republic in southern Europe on the Italian Peninsula; was the core of the Roman Republic and the Roman Empire between the 4th century BC and the 5th century AD