greater whitethroat vs warbler

greater whitethroat and warbler both are nouns.

Word	Noun	Adjective	Verb	Adverb
greater whitethroat	Yes	No	No	No
warbler	Yes	No	No	No

As nouns, warbler is a hypernym of greater whitethroat; that is, warbler is a word with a broader meaning than greater whitethroat:

greater whitethroat: greyish-brown Old World warbler with a white throat and underparts
warbler: a small active songbird

greater whitethroat (noun)	warbler (noun)
greyish-brown Old World warbler with a white throat and underparts	a small active songbird
	a singer; usually a singer who adds embellishments to the song