Anglesea vs Anglesey Island

Anglesea and Anglesey Island both are nouns.

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

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

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

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