water ouzel vs oscine

water ouzel and oscine both are nouns.

Word	Noun	Adjective	Verb	Adverb
water ouzel	Yes	No	No	No
oscine	Yes	Yes	No	No

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

water ouzel: small stocky diving bird without webbed feet; frequents fast-flowing streams and feeds along the bottom
oscine: passerine bird having specialized vocal apparatus

Other hypernyms of water ouzel include oscine bird.

water ouzel (noun)	oscine (noun)
small stocky diving bird without webbed feet; frequents fast-flowing streams and feeds along the bottom	passerine bird having specialized vocal apparatus

water ouzel (adjective)	oscine (adjective)
	of or relating to the songbirds