jungle fowl vs gallinacean

jungle fowl and gallinacean both are nouns.

Word	Noun	Adjective	Verb	Adverb
jungle fowl	Yes	No	No	No
gallinacean	Yes	No	No	No

As nouns, gallinacean is a hypernym of jungle fowl; that is, gallinacean is a word with a broader meaning than jungle fowl:

jungle fowl: small Asiatic wild bird; believed to be ancestral to domestic fowl
gallinacean: heavy-bodied largely ground-feeding domestic or game birds

Other hypernyms of jungle fowl include gallinaceous bird.

jungle fowl (noun)	gallinacean (noun)
small Asiatic wild bird; believed to be ancestral to domestic fowl	heavy-bodied largely ground-feeding domestic or game birds