American oriole vs oriole

American oriole and oriole both are nouns.

Word	Noun	Adjective	Verb	Adverb
American oriole	Yes	No	No	No
oriole	Yes	No	No	No

As nouns, American oriole and oriole are synonyms defined as:

American oriole and oriole: American songbird; male is black and orange or yellow

Other synonyms of American oriole include New World oriole.

American oriole (noun)	oriole (noun)
American songbird; male is black and orange or yellow	American songbird; male is black and orange or yellow
	mostly tropical songbird; the male is usually bright orange and black