General English

Cars & Driving

  • noun a liquid-to-air heat exchanger that transfers engine heat to the outside air; consists of many thin-walled tubes with metal cooling fins that draw off heat from the liquid (predominantly water) inside them
  • abbreviationrad


  • A visually exposed heat exchanger consisting of a series of pipes that allows the circulation of steam or hot water. The heat from the steam or hot water is given up to the air surrounding the pipes.


  • Any particle, body, material, or system, which emits radiation.
  • The part of an antenna or element which emits radio waves. Also called antenna radiator.
  • A device or surface which vibrates to produce sound waves. Examples include headphone diaphragms, speaker cones, and distributed-mode speaker panels. Also called acoustic radiator, or sound radiator. 4, An enclosure which is sealed, except for a small opening through which radiant energy may enter or escape. The radiation of such an enclosure approximates that of a blackbody. Also called cavity radiator.

Real Estate

  • noun a room-heating device that emits heat from pipes through which hot water, steam, or hot oil circulates, especially one connected to a central boiler-fed system