quill vs tail feather

quill and tail feather both are nouns.

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

As nouns, tail feather is a hyponym of quill; that is, tail feather is a word with a more specific, narrower meaning than quill:

Other hyponyms of quill include primary, primary feather, primary quill.

quill (noun)	tail feather (noun)
a stiff hollow protective spine on a porcupine or hedgehog	feather growing from the tail (uropygium) of a bird
the hollow spine of a feather
any of the larger wing or tail feathers of a bird
pen made from a bird's feather