Tahiti vs island

Tahiti and island both are nouns.

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

Tahiti (noun)	island (noun)
an island in the south Pacific; the most important island in French Polynesia; made famous by Robert Louis Stevenson and Paul Gauguin	a zone or area resembling an island
	a land mass (smaller than a continent) that is surrounded by water