poorwill vs goatsucker

poorwill and goatsucker both are nouns.

Word	Noun	Adjective	Verb	Adverb
poorwill	Yes	No	No	No
goatsucker	Yes	No	No	No

As nouns, goatsucker is a hypernym of poorwill; that is, goatsucker is a word with a broader meaning than poorwill:

poorwill: goatsucker of western North America
goatsucker: mainly crepuscular or nocturnal nonpasserine birds with mottled greyish-brown plumage and large eyes; feed on insects

Other hypernyms of poorwill include caprimulgid, nightjar.

poorwill (noun)	goatsucker (noun)
goatsucker of western North America	mainly crepuscular or nocturnal nonpasserine birds with mottled greyish-brown plumage and large eyes; feed on insects