spurious wing vs plumage

spurious wing and plumage both are nouns.

Word	Noun	Adjective	Verb	Adverb
spurious wing	Yes	No	No	No
plumage	Yes	No	No	No

As nouns, plumage is a hypernym of spurious wing; that is, plumage is a word with a broader meaning than spurious wing:

spurious wing: tuft of small stiff feathers on the first digit of a bird's wing
plumage: the light horny waterproof structure forming the external covering of birds

Other hypernyms of spurious wing include plume.

spurious wing (noun)	plumage (noun)
tuft of small stiff feathers on the first digit of a bird's wing	the light horny waterproof structure forming the external covering of birds