Singapore Island vs island

Singapore Island and island both are nouns.

Word	Noun	Adjective	Verb	Adverb
Singapore Island	Yes	No	No	No
island	Yes	No	No	No

Singapore Island (noun)	island (noun)
an island to the south of the Malay Peninsula	a zone or area resembling an island
	a land mass (smaller than a continent) that is surrounded by water