Source : Webster's Revised Unabridged Dictionary (1913)

Perissodactyl \Per`is*so*dac"tyl\, n. (Zo["o]l.)
   One of the Perissodactyla.

Source : WordNet®

perissodactyl
     n : placental mammals having hooves with an odd number of toes
         on each foot [syn: {odd-toed ungulate}, {perissodactyl
         mammal}] [ant: {even-toed ungulate}]