Entry 2 senses · 2 variants Webster, 1913 Heterodactyl · Het·er·o·dac·tyl · IPA a. n. pl. 01 a. Heterodactylous. 1. Heterodactylous.(Zool.) 02 n. pl. A group of birds including the trogons. 1. A group of birds including the trogons.(Zool.)