Guadalupe Island vs island

Guadalupe Island and island both are nouns.

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

Guadalupe Island (noun)	island (noun)
a Mexican island in the Pacific to the west of Baja California	a zone or area resembling an island
	a land mass (smaller than a continent) that is surrounded by water