What is another word for poikilotherm?
Pronunciation: [pˈɔ͡ɪkɪlˌʌðɜːm] (IPA) 
Poikilotherm is a word that refers to an organism that needs external heat sources to regulate its body temperature. This category includes amphibians, reptiles, and some fish. There are several synonyms for poikilotherm, including ectotherm, heterotherm, cold-blooded, and thermoconformers. Ectotherm refers to an organism that derives heat from the external environment, whereas heterotherm refers to an organism that can vary its internal temperature. Cold-blooded, on the other hand, refers to organisms that do not have a constant internal temperature. Finally, thermoconformers are organisms that simply conform to the temperature of their environment. All of these words are used to describe the same trait: the inability to maintain an internal body temperature.
