a unique South American gallinaceous bird, Opisthocomus hoazin, with a brownish plumage, a very small crested head, and clawed wing digits in the young: family Opisthocomidae
Word origin
C17: from American Spanish, from Nahuatl uatzin pheasant
hoatzin in American English
(hoʊˈætsɪn; wɑtˈsin)
noun
a crested South American bird (Opisthocomus hoazin) of an order (Opisthocomiformes) with only one species: the wings of its young have claws