European blackbird vs ousel

European blackbird and ousel both are nouns.

Word	Noun	Adjective	Verb	Adverb
European blackbird	Yes	No	No	No
ousel	Yes	No	No	No

As nouns, European blackbird and ousel are synonyms defined as:

Other synonyms of European blackbird include blackbird, merl, merle, ouzel, Turdus merula.

European blackbird (noun)	ousel (noun)
common black European thrush	common black European thrush