Cape Breton Island vs island

Cape Breton Island and island both are nouns.

Word	Noun	Adjective	Verb	Adverb
Cape Breton Island	Yes	No	No	No
island	Yes	No	No	No

Cape Breton Island (noun)	island (noun)
an island that forms the northeastern part of Nova Scotia	a zone or area resembling an island
	a land mass (smaller than a continent) that is surrounded by water