Merriam-Webster Collegiate Dictionary - rhinoceros

 noun  (plural -noceroses; also -noceros or rhinoceri)  Etymology: Middle English rinoceros, from Anglo-French, from Latin rhinocerot-, ~, from Greek rhinokerot-, rhinokeros, from rhin- + keras horn — more at horn  Date: 14th century any of a family (Rhinocerotidae) of large heavyset herbivorous perissodactyl mammals of Africa and Asia that have one or two upright keratinous horns on the snout and thick gray to brown skin with little hair