mockingbird vs oscine bird

mockingbird and oscine bird both are nouns.

Word	Noun	Adjective	Verb	Adverb
mockingbird	Yes	No	No	No
oscine bird	Yes	No	No	No

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

mockingbird: long-tailed grey-and-white songbird of the southern United States able to mimic songs of other birds
oscine bird: passerine bird having specialized vocal apparatus

Other hypernyms of mockingbird include oscine.

mockingbird (noun)	oscine bird (noun)
long-tailed grey-and-white songbird of the southern United States able to mimic songs of other birds	passerine bird having specialized vocal apparatus