The Collaborative International Dictionary of English v.0.48:

Zygodactylic \Zyg`o*dac"ty*lic\, Zygodactylous
\Zyg`o*dac"tyl*ous\ (?; 277), a. [Gr. zygo`n a yoke, pair + ?
   finger, toe: cf. F. zygodactyle.] (Zool.)
   Yoke-footed; having the toes disposed in pairs; -- applied to
   birds which have two toes before and two behind, as the
   parrot, cuckoo, woodpecker, etc.
   [1913 Webster]