Anglesey Island vs Anglesea Island

Anglesey Island and Anglesea Island both are nouns.

Word	Noun	Adjective	Verb	Adverb
Anglesey Island	Yes	No	No	No
Anglesea Island	Yes	No	No	No

As nouns, Anglesey Island and Anglesea Island are synonyms defined as:

Anglesey Island and Anglesea Island: an island to the northwest of Wales

Other synonyms of Anglesey Island include Anglesea, Anglesey, Mona.

Anglesey Island (noun)	Anglesea Island (noun)
an island to the northwest of Wales	an island to the northwest of Wales