What does homoeothermic mean?
Homoeothermic describes an animal that keeps its body temperature relatively constant, chiefly by producing heat through its own metabolism. Birds and mammals are familiar examples, as are some fish and other animals with substantial physiological control over their internal temperatures. The term is more precise than the informal phrase “warm-blooded” and is especially useful in biology when comparing animals whose body temperatures rise and fall with the environment. In technical discussions, homoeothermic animals are commonly contrasted with poikilothermic animals, whose body temperatures vary substantially with ambient conditions, and ectothermic animals, which rely primarily on external heat sources. Although homoeothermy does not mean that body temperature never changes, it indicates active regulation that limits variation. The word is formal and specialized rather than everyday, but it clearly captures an important distinction in animal physiology.
adjectiveRelating to or designating an organism that maintains a relatively constant internal body temperature, chiefly through metabolic heat production, largely independently of the surrounding temperature.
- Of or relating to an organism that maintains a relatively constant body temperature through internal physiological processes.
"Most birds and mammals are homoeothermic, maintaining a stable body temperature despite changing environmental conditions."
"Most mammals are homoeothermic, using metabolic heat to maintain a nearly constant internal temperature."
"The study compared the energy demands of homoeothermic birds with those of ectothermic reptiles."
Birds and mammals carry their own furnaces, keeping their bodies warm even when the environment turns bitterly cold.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does homoeothermic come from?
Homoeothermic combines Greek homoios, meaning “like” or “similar,” with Greek thermos, meaning “heat,” and the adjectival suffix -ic. It developed as a zoological term for organisms capable of maintaining a relatively constant internal temperature. The related noun homoeothermy names this physiological process, while homeothermic reflects an alternative English spelling; both are cognates of broader English words such as thermal and thermometer.
Related word forms
How homoeothermic is actually used
This is chiefly a scientific or zoological term. It is more precise than the informal expression “warm-blooded” and is often contrasted with poikilothermic or ectothermic. Both homoeothermic and homeothermic spellings are used.
Easily confused with homoeothermic
Homeothermic is a widely used spelling variant of homoeothermic, and the two words have the same meaning.