contour feather vs plumage

contour feather and plumage both are nouns.

Word	Noun	Adjective	Verb	Adverb
contour feather	Yes	No	No	No
plumage	Yes	No	No	No

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

contour feather: feathers covering the body of an adult bird and determining its shape
plumage: the light horny waterproof structure forming the external covering of birds

Other hypernyms of contour feather include plume.

contour feather (noun)	plumage (noun)
feathers covering the body of an adult bird and determining its shape	the light horny waterproof structure forming the external covering of birds