tyrant bird vs phoebe

tyrant bird and phoebe both are nouns.

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

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

tyrant bird: large American birds that characteristically catch insects on the wing
phoebe: small dun-colored North American flycatcher

tyrant bird (noun)	phoebe (noun)
large American birds that characteristically catch insects on the wing	small dun-colored North American flycatcher