The Collaborative International Dictionary of English v.0.48:

artiodactyl \artiodactyl\ n.
   1. placental mammal having hooves with an even number of
      functional toes on each foot; a member of the
      artiodactyla.

   Syn: artiodactyle, even-toed ungulate, artiodactyl mammal
        [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

artiodactyl \artiodactyl\ adj.
   of, pertaining to, or belonging to the order Artiodactyla.

   Syn: artiodactylous, even-toed.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

artiodactyl
    adj 1: of or relating to or belonging to mammals of the order
           Artiodactyla [syn: artiodactyl, artiodactylous,
           even-toed]
    n 1: placental mammal having hooves with an even number of
         functional toes on each foot [syn: even-toed ungulate,
         artiodactyl, artiodactyl mammal] [ant: odd-toed
         ungulate, perissodactyl, perissodactyl mammal]