The Collaborative International Dictionary
Heterodactylous
Heterodactylous \Het`er*o*dac"tyl*ous\, a. [Hetero- + Gr. ? a toe.] (Zo["o]l.) Having the first and second toes turned backward, as in the trogons.
Wiktionary
heterodactylous
a. (context zoology English) Having the first and second toes turned backward, as in the trogons.