Ectothermic

Part of speech: adjective

Definitions

1. A designation for living beings that depend on external sources to regulate their body temperature
2. Pertains to organisms that cannot produce sufficient internal heat and must rely on their environment for warmth
3. A term describing species that rely on ambient temperatures for thermal regulation and cannot generate adequate heat internally

Etymology: Ectothermic is a compound built in two stages. The core is "ectotherm," coined from Greek roots: "ektos," meaning "outside," and "thermē," meaning "heat." An ectotherm is an animal whose body heat comes mainly from its surroundings, so the word literally describes warmth taken from outside the body. Nothing about the term existed in ancient Greek; it is a modern scientific coinage built from classical parts. The adjective ending "-ic" arrived by a long and winding route. It descends from a Proto-Indo-European suffix meaning roughly "having the nature of," passed into Proto-Italic and Latin as "-icus," then reached English through Old French "-ique" and Middle English "-ik." The form in ectothermic is therefore an ancient suffix attached to a very recent scientific word.

Synonyms: cold-blooded

Antonyms: endothermic, warm-blooded