firebird vs tyrant bird

firebird and tyrant bird both are nouns.

Word	Noun	Adjective	Verb	Adverb
firebird	Yes	No	No	No
tyrant bird	Yes	No	No	No

As nouns, tyrant bird is a hypernym of firebird; that is, tyrant bird is a word with a broader meaning than firebird:

firebird: tropical American flycatcher found as far north as southern Texas and Arizona; adult male has bright scarlet and black plumage
tyrant bird: large American birds that characteristically catch insects on the wing

Other hypernyms of firebird include flycatcher, New World flycatcher, tyrant flycatcher.

firebird (noun)	tyrant bird (noun)
eastern subspecies of northern oriole	large American birds that characteristically catch insects on the wing
the male is bright red with black wings and tail
tropical American flycatcher found as far north as southern Texas and Arizona; adult male has bright scarlet and black plumage