exothermic

Etymology

From French exothermique, from exo- (“outside”) + thermique (“of heat”), both ultimately from Ancient Greek.

adj

1. (chemistry, of a reaction) That releases energy in the form of heat.
2. (chemistry, of a compound) That releases heat during its formation, and absorbs it during its decomposition.
3. (zoology) Of an animal: whose body temperature is regulated by external factors; cold-blooded.