island vs Nantucket

island and Nantucket both are nouns.

Word	Noun	Adjective	Verb	Adverb
island	Yes	No	No	No
Nantucket	Yes	No	No	No

island (noun)	Nantucket (noun)
a zone or area resembling an island	an island resort off Cape Cod; formerly a center of the whaling industry
a land mass (smaller than a continent) that is surrounded by water