New Siberian Islands vs island

New Siberian Islands and island both are nouns.

Word	Noun	Adjective	Verb	Adverb
New Siberian Islands	Yes	No	No	No
island	Yes	No	No	No

New Siberian Islands (noun)	island (noun)
a group of islands in the Arctic Ocean to the north of Siberia and to the east of the Laptev Sea	a zone or area resembling an island
	a land mass (smaller than a continent) that is surrounded by water