poikilotherm

poi·ki·lo·therm

noun
\ˈpȯi-ki-lə-ˌthərm, (ˌ)pȯi-ˈkil-ə-\

Definition of POIKILOTHERM

: an organism (as a frog) with a variable body temperature that is usually slightly higher than the temperature of its environment : a cold-blooded organism—called also heterotherm