bird nest vs aerie

bird nest and aerie both are nouns.

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

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

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

bird nest (noun)	aerie (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)