bird nest vs eyry

bird nest and eyry both are nouns.

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

As nouns, eyry is a hyponym of bird nest; that is, eyry is a word with a more specific, narrower meaning than bird nest:

Other hyponyms of bird nest include aerie, aery, eyrie.

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