What is "poikilothermic"

Poikilothermal \Poi`ki*lo*ther"mal\ (-th[~e]r"mal), Poikilothermic \Poi`ki*lo*ther"mic\ (-th[~e]r"m[i^]k), a. [Gr. poiki`los changeable + E. thermal, thermic.] (Physiol.) Having a varying body temperature. See Homoiothermal.

a. (context of an animal English) Having a body temperature that varies depending on the outside temperature.

adj. of animals except birds and mammals; having body temperature that varies with the environment [syn: poikilothermous, heterothermic, ectothermic]