fairy bluebird vs oscine bird

fairy bluebird and oscine bird both are nouns.

Word	Noun	Adjective	Verb	Adverb
fairy bluebird	Yes	No	No	No
oscine bird	Yes	No	No	No

As nouns, oscine bird is a hypernym of fairy bluebird; that is, oscine bird is a word with a broader meaning than fairy bluebird:

fairy bluebird: fruit-eating mostly brilliant blue songbird of the East Indies
oscine bird: passerine bird having specialized vocal apparatus

Other hypernyms of fairy bluebird include oscine.

fairy bluebird (noun)	oscine bird (noun)
fruit-eating mostly brilliant blue songbird of the East Indies	passerine bird having specialized vocal apparatus