scrub fowl vs gallinaceous bird

scrub fowl and gallinaceous bird both are nouns.

Word	Noun	Adjective	Verb	Adverb
scrub fowl	Yes	No	No	No
gallinaceous bird	Yes	No	No	No

As nouns, gallinaceous bird is a hypernym of scrub fowl; that is, gallinaceous bird is a word with a broader meaning than scrub fowl:

scrub fowl: large-footed short-winged birds of Australasia; build mounds of decaying vegetation to incubate eggs
gallinaceous bird: heavy-bodied largely ground-feeding domestic or game birds

Other hypernyms of scrub fowl include gallinacean.

scrub fowl (noun)	gallinaceous bird (noun)
large-footed short-winged birds of Australasia; build mounds of decaying vegetation to incubate eggs	heavy-bodied largely ground-feeding domestic or game birds