The Collaborative International Dictionary of English v.0.48:

Homoiothermal \Ho*moi`o*ther"mal\, Homoiothermic
\Ho*moi`o*therm"ic\, a. [Gr. ? like + E. thermal.] (Physiol.)
   Maintaining a uniform body temperature, usually above the
   ambient temperature; h[ae]matothermal; homothermic;
   warm-blooded; -- applied to warm-bodied animals such as birds
   and mammals, because they maintain a nearly uniform
   temperature in spite of the great variations in the
   surrounding air; in distinct from the cold-blooded
   (poikilothermal) animals, whose body temperature follows
   the variations in temperature of the surrounding medium.

   Syn: homeothermal, homeothermic, homothermal, homothermic,
        homoiothermic.
        [1913 Webster] homoiothermism

WordNet (r) 3.0 (2006):

homoiothermic
    adj 1: of birds and mammals; having constant and relatively high
           body temperature [syn: homoiothermic, homeothermic,
           homothermic]