(poy´ kill o therm) [Gr. poikilos: varied + therme: heat] • An animal whose body temperature tends to vary with the surrounding environment. (Contrast with homeotherm, heterotherm.)

an animal whose body temperature varies with the temperature of its surroundings; any animal except birds and mammals

organism whose internal body temperature varies with and remains close to environmental temperature; poikilotherms were once called "cold-blooded"

An animal whose body temperature varies with the surrounding environment (e.g. amphibians and fish).