Answer:
Any action - chemical, physical, electrical or atomic - that gives off heat energy is exothermic. A few examples are a light bulb, a campfire, your computer CPU (when in use) and rubbing two sticks together. "Exo" and "thermic" are both combined forms from early Greek, the one meaning "out" or "outward", the other meaning "heat". The opposite is "endothermic", "endo" meaning "in" or "inward".