great bustard vs bustard

great bustard and bustard both are nouns.

Word	Noun	Adjective	Verb	Adverb
great bustard	Yes	No	No	No
bustard	Yes	No	No	No

As nouns, bustard is a hypernym of great bustard; that is, bustard is a word with a broader meaning than great bustard:

great bustard: largest European land bird
bustard: large heavy-bodied chiefly terrestrial game bird capable of powerful swift flight; classified with wading birds but frequents grassy steppes

great bustard (noun)	bustard (noun)
largest European land bird	large heavy-bodied chiefly terrestrial game bird capable of powerful swift flight; classified with wading birds but frequents grassy steppes