Madeira vs Madeira River

Madeira and Madeira River both are nouns.

Word	Noun	Adjective	Verb	Adverb
Madeira	Yes	No	No	No
Madeira River	Yes	No	No	No

As nouns, Madeira and Madeira River are synonyms defined as:

Madeira and Madeira River: a 3380 km long Brazilian river; tributary of the Amazon River

Madeira (noun)	Madeira River (noun)
an amber dessert wine from the Madeira Islands	a 3380 km long Brazilian river; tributary of the Amazon River
an island in the Atlantic Ocean off the coast of Africa; the largest of the Madeira Islands
a 3380 km long Brazilian river; tributary of the Amazon River