Zanzibar vs island

Zanzibar and island both are nouns.

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

Zanzibar (noun)	island (noun)
an island in the Indian Ocean off the east coast of Africa; part of the United Republic of Tanzania	a zone or area resembling an island
	a land mass (smaller than a continent) that is surrounded by water