8 Wintry Words to Defrost Your Vocabulary
1858, as a proposed word for "electricity," from pyro- + -gen. Meaning "fever-producer" is from 1896. Related: Pyrogenic; pyrogenetic. Greek pyrogenes meant "born in fire, wrought by fire."
pyrogen py·ro·gen (pī'rə-jən)n. A substance that produces a fever.