Radiator

Part of speech: noun

Pronunciation: /ˈrædɪeɪ̯tə/

Definitions

1. A heating apparatus that transfers warmth from circulating fluids to the surrounding air while regulating indoor temperatures
2. A device used for heating that transfers thermal energy from hot fluids to the air in a room while helping to maintain a comfortable climate
3. An appliance designed to emit heat via circulating liquids, allowing for temperature control within a space

Etymology: The modern heater on your wall gets its name from a physics term that predates it by centuries. "Radiate" comes from Latin "radiare," meaning to shine or emit rays, built on "radius," the spoke of a wheel or a ray of light. A radiator, in the original sense, is simply the thing that sends out heat or light in all directions, which is why the name fits a metal panel warming a room by emitting heat rather than by blowing air. The suffix "-or" marks an agent, something that performs the action, so a radiator is literally "that which radiates." English took the form directly from the verb, and the heating sense followed the older physical meaning of giving off heat, which is why the same word covers the car-engine cooler as well. A related form, "radiatori," appears in Italian, and the two are doublets, words that split from one Latin source and entered English by different routes.

Synonyms: heater, condenser, cooler, fan, coil