• (a.) Having the first and second toes turned backward, as in the trogons.
Het`er·o·dac'tyl·ous adjective [ Hetero- + Greek ... a toe.] (Zoology) Having the first and second toes turned backward, as in the trogons. 
heterodactyl, heterodactylous Having the toes, or one of them, irregular or abnormal, as certain families of birds.