Bahrain Island vs Bahrein

Bahrain Island and Bahrein both are nouns.

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

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

Other synonyms of Bahrain Island include Bahrain, Bahrein Island.

Bahrain Island (noun)	Bahrein (noun)
an island in the Persian Gulf	an island country in the Persian Gulf off the coast of Saudi Arabia; oil revenues funded progressive programs until reserves were exhausted in 1970s
	an island in the Persian Gulf