perissodactyl

from WordNet (r) 3.0 (2006)

perissodactyl
    n 1: placental mammals having hooves with an odd number of toes
         on each foot [syn: {odd-toed ungulate}, {perissodactyl},
         {perissodactyl mammal}] [ant: {artiodactyl}, {artiodactyl
         mammal}, {even-toed ungulate}]

from The Collaborative International Dictionary of English v.0.48

Perissodactyl \Per`is*so*dac"tyl\, n. (Zool.)
   One of the Perissodactyla.
   [1913 Webster]