Perissad :: Perissad (a.) Odd; not even; -- said of elementary substances and of radicals whose valence is not divisible by two without a remainder. Contrasted with artiad.
Perissodactyla :: Perissodactyla (n. pl.) A division of ungulate mammals, including those that have an odd number of toes, as the horse, tapir, and rhinoceros; -- opposed to Artiodactyla..