island vs Formosa

island and Formosa both are nouns.

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

island (noun)	Formosa (noun)
a zone or area resembling an island	an island in southeastern Asia 100 miles off the coast of mainland China in the South China Sea
a land mass (smaller than a continent) that is surrounded by water