columbiform bird vs gallinacean

columbiform bird and gallinacean both are nouns.

Word	Noun	Adjective	Verb	Adverb
columbiform bird	Yes	No	No	No
gallinacean	Yes	No	No	No

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

columbiform bird: a cosmopolitan order of land birds having small heads and short legs with four unwebbed toes
gallinacean: heavy-bodied largely ground-feeding domestic or game birds

Other hypernyms of columbiform bird include gallinaceous bird.

columbiform bird (noun)	gallinacean (noun)
a cosmopolitan order of land birds having small heads and short legs with four unwebbed toes	heavy-bodied largely ground-feeding domestic or game birds