plain turkey vs bustard

plain turkey and bustard both are nouns.

Word	Noun	Adjective	Verb	Adverb
plain turkey	Yes	No	No	No
bustard	Yes	No	No	No

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

plain turkey: popular Australian game bird
bustard: large heavy-bodied chiefly terrestrial game bird capable of powerful swift flight; classified with wading birds but frequents grassy steppes

plain turkey (noun)	bustard (noun)
popular Australian game bird	large heavy-bodied chiefly terrestrial game bird capable of powerful swift flight; classified with wading birds but frequents grassy steppes