What does homeotherm mean?
Homeotherm is a technical biology term for an organism that keeps its internal body temperature relatively constant, largely by producing metabolic heat rather than relying directly on the temperature of its surroundings. Mammals and birds are the best-known examples, while many fish, reptiles, and other animals are instead described as poikilotherms, whose body temperatures vary with the environment. The word is especially useful when discussing physiology, thermoregulation, and the energetic costs of maintaining a stable internal temperature. It should not automatically be treated as an exact synonym for endotherm: endothermy means deriving heat from within the body, whereas homeothermy specifically emphasizes a stable temperature. Although homeotherm can describe humans and other familiar animals, the term is primarily used in scientific and educational contexts rather than everyday speech.
nounAn organism, especially an animal, that maintains a relatively constant internal body temperature, largely independently of the temperature of its surroundings.
- An organism that maintains a relatively constant internal body temperature, largely independently of environmental temperature.
"Mammals and birds are familiar examples of homeotherms."
"The researcher compared the energy demands of a homeotherm with those of a poikilotherm."
"Humans are homeotherms, using metabolic heat and behavioral responses to regulate body temperature."
The regular plural is used when referring to multiple organisms that maintain relatively constant internal body temperatures.
"Birds and mammals are the best-known homeotherms."
A homeotherm carries its own thermal weather system: its body can stay warm while the world around it turns cold.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does homeotherm come from?
Homeotherm combines the Greek roots homos, meaning “same,” and thermos, meaning “hot” or “warm.” The scientific term was formed to express the characteristic of maintaining a body temperature that remains approximately the same despite changes in environmental conditions. Its counterparts share the same thermal root, including therm, thermometer, thermostat, and thermophile.
Related word forms
How homeotherm is actually used
This is a technical term in comparative physiology and ecology. It is often used in discussion of animals, but it can apply more broadly to any organism with a stable internal temperature. Endotherm is a related but broader term: an endotherm produces internal heat without necessarily maintaining a nearly constant body temperature.
Easily confused with homeotherm
Homoeotherm is an alternative spelling of homeotherm, not a different concept.
A heterotherm can vary its body temperature substantially, whereas a homeotherm maintains a relatively stable internal temperature.