noun ·Rare ·Advanced level

Definitions

Noun

1. 1
   A cold-blooded animal: one, such as an amphibian, fish, reptile, or arthropod, which has a limited ability to regulate its body temperature and whose body temperature thus depends on the ambient temperature.
2. 2
   an animal whose body temperature varies with the temperature of its surroundings; any animal except birds and mammals wordnet

Synonyms

All synonyms

poikilothermpoikilotherm

Antonyms

All antonyms

endothermhomeothermhomoeothermhomoiotherm

Etymology

From ecto- + -therm.

Related phrases

cold blooded

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.