Madeira Islands vs Madeiras

Madeira Islands and Madeiras both are nouns.

Word	Noun	Adjective	Verb	Adverb
Madeira Islands	Yes	No	No	No
Madeiras	Yes	No	No	No

As nouns, Madeira Islands and Madeiras are synonyms defined as:

Madeira Islands and Madeiras: a group of volcanic islands in the Atlantic Ocean to the west of Morocco; the group forms an autonomous region of Portugal

Madeira Islands (noun)	Madeiras (noun)
a group of volcanic islands in the Atlantic Ocean to the west of Morocco; the group forms an autonomous region of Portugal	a group of volcanic islands in the Atlantic Ocean to the west of Morocco; the group forms an autonomous region of Portugal