poikilothermism

Or poi·ki·lo·ther·my

[poi-kuh-loh-thur-miz-uhm, poi-kil-uh-]

noun

Zoology.

1. the state or quality of being cold-blooded, as fishes and reptiles.

Word History and Origins

Origin of poikilothermism¹

First recorded in 1900–05; from Greek poikilos “various” + therm- ( def. ) + -ism ( def. )