Bahrain Island vs Bahrein Island

Bahrain Island and Bahrein Island both are nouns.

Word	Noun	Adjective	Verb	Adverb
Bahrain Island	Yes	No	No	No
Bahrein Island	Yes	No	No	No

As nouns, Bahrain Island and Bahrein Island are synonyms defined as:

Other synonyms of Bahrain Island include Bahrain, Bahrein.

Bahrain Island (noun)	Bahrein Island (noun)
an island in the Persian Gulf	an island in the Persian Gulf