flycatcher vs oscine

flycatcher and oscine both are nouns.

Word	Noun	Adjective	Verb	Adverb
flycatcher	Yes	No	No	No
oscine	Yes	Yes	No	No

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

flycatcher: any of a large group of small songbirds that feed on insects taken on the wing
oscine: passerine bird having specialized vocal apparatus

Other hypernyms of flycatcher include oscine bird.

flycatcher (noun)	oscine (noun)
any of a large group of small songbirds that feed on insects taken on the wing	passerine bird having specialized vocal apparatus
large American birds that characteristically catch insects on the wing

flycatcher (adjective)	oscine (adjective)
	of or relating to the songbirds