Aegean island vs island

Aegean island and island both are nouns.

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

As nouns, island is a hypernym of Aegean island; that is, island is a word with a broader meaning than Aegean island:

Aegean island (noun)	island (noun)
an island in the Aegean Sea	a zone or area resembling an island
	a land mass (smaller than a continent) that is surrounded by water