Zygodactylic

Zyg`o`dac´ty`lica.1.(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.Webster’s Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.