island vs Yezo

island and Yezo both are nouns.

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

island (noun)	Yezo (noun)
a zone or area resembling an island	the second largest of the four main islands of Japan; to the north of Honshu
a land mass (smaller than a continent) that is surrounded by water