The Collaborative International Dictionary of English v.0.48:

homeotherm \homeotherm\ n. (Biol.)
   A homoiothermal animal.

   Syn: homoiotherm.
        [PJC] homeothermal

WordNet (r) 3.0 (2006):

homeotherm
    n 1: an animal that has a body temperature that is relatively
         constant and independent of the environmental temperature
         [syn: homeotherm, homoiotherm, homotherm]