island vs Zanzibar

island and Zanzibar both are nouns.

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

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