bird nest vs eyrie

bird nest and eyrie both are nouns.

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

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

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

bird nest (noun)	eyrie (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)