Poikilothermic

Part of speech: adjective

Definitions

1. An organism characterized by a temperature regulation method that depends on the external environment, leading to fluctuating internal body temperatures A life form that adjusts its body temperature according to the ambient conditions, lacking internal thermoregulation mechanisms A creature whose physiological processes are influenced by external temperatures, resulting in variable body heat levels
2. A living organism that regulates its body temperature through external environmental conditions, leading to variations in metabolic processes
3. Describes a living being that does not maintain a constant internal temperature but changes it in response to the temperature around it

Etymology: Poikilothermic is a technical coinage built from two Greek roots. "Poikilos" meant "many-coloured," "dappled," or "variegated," and it was used of things with mixed or varied patterns, such as embroidery or a spotted animal. "Thermos" meant "hot" or "heat," the same root that gives "thermometer" and "thermal." The "-ic" ending turns the combined stem into an adjective, so the word literally means something like "of varied heat." The surprise lies in the first element. Ancient Greek writers used "poikilos" for a wide range of variegated things, and modern scientists borrowed it for a physiological idea: animals whose body temperature shifts with their surroundings. The older, more familiar term for such creatures was "cold-blooded," which is a loose description of the same condition. "Poikilothermic" is the precise version, and it was built from classical parts rather than inherited from ancient texts, so no Greek speaker ever used it of lizards or fish.

Synonyms: cold-blooded, ectothermic, variable-temperature

Antonyms: homeothermic, warm-blooded