primary quill vs primary feather

primary quill and primary feather both are nouns.

Word	Noun	Adjective	Verb	Adverb
primary quill	Yes	No	No	No
primary feather	Yes	No	No	No

As nouns, primary quill and primary feather are synonyms defined as:

primary quill and primary feather: one of the main flight feathers projecting along the outer edge of a bird's wing

Other synonyms of primary quill include primary.

primary quill (noun)	primary feather (noun)
one of the main flight feathers projecting along the outer edge of a bird's wing	one of the main flight feathers projecting along the outer edge of a bird's wing