archipelago vs Ellice Islands

archipelago and Ellice Islands both are nouns.

Word	Noun	Adjective	Verb	Adverb
archipelago	Yes	No	No	No
Ellice Islands	Yes	No	No	No

archipelago (noun)	Ellice Islands (noun)
a group of many islands in a large body of water	a group of coral islands in Micronesia to the southwest of Hawaii