passeriform bird vs Passeriformes

passeriform bird and Passeriformes both are nouns.

Word	Noun	Adjective	Verb	Adverb
passeriform bird	Yes	No	No	No
Passeriformes	Yes	No	No	No

passeriform bird (noun)	Passeriformes (noun)
perching birds mostly small and living near the ground with feet having 4 toes arranged to allow for gripping the perch; most are songbirds; hatchlings are helpless	largest order of birds comprising about half the known species: rooks, finches, sparrows, tits, warblers, robins, wrens, swallows, etc.; the four suborders are Eurylaimi, Tyranni, Menurae and Oscines or Passeres