eyry vs bird's nest

eyry and bird's nest both are nouns.

Word	Noun	Adjective	Verb	Adverb
eyry	Yes	No	No	No
bird's nest	Yes	No	No	No

As nouns, bird's nest is a hypernym of eyry; that is, bird's nest is a word with a broader meaning than eyry:

Other hypernyms of eyry include bird nest, birdnest.

eyry (noun)	bird's nest (noun)
any habitation at a high altitude	nest where birds lay their eggs and hatch their young
the lofty nest of a bird of prey (such as a hawk or eagle)