Hawaii Island vs Hawaii

Hawaii Island and Hawaii both are nouns.

Word	Noun	Adjective	Verb	Adverb
Hawaii Island	Yes	No	No	No
Hawaii	Yes	No	No	No

As nouns, Hawaii Island and Hawaii are synonyms defined as:

Hawaii Island and Hawaii: the largest and southernmost of the Hawaii islands; has several volcanic peaks

Hawaii Island (noun)	Hawaii (noun)
the largest and southernmost of the Hawaii islands; has several volcanic peaks	a state in the United States in the central Pacific on the Hawaiian Islands
	the largest and southernmost of the Hawaii islands; has several volcanic peaks