zygodactyloushttp://www.oed.com/dictionary/zygodactylous_adj%3Ftab%3Dmeaning_and_usezygodactylous, adj.
First published 1921; not fully revised

zygodactylousadjective

Ornithology.
  1. 1828–
    Stressed as zygoˈdactylous.
    1. 1828–32
      Zygodactylous.
      N. Webster, American Dictionary of English Language
    2. 1890

Originally published as part of the entry for zygodactyl, adj. & n.

zygodactyl, adj. & n. was first published in 1921; not fully revised.