A room in an old house is often heated by a radiator, a metal device made up of pipes that circulate steam or hot water.

If your house is heated with radiators, there will usually be one in each room, all connected to a central heating system. A radiator gets hot, and it sends that heat out into the room — in other words, it radiates heat. In fact, the word radiator originally meant "anything that radiates," including heat, light, or energy. By the 1850's, radiator had come to primarily mean "heater in a building or house."

Definitions of radiator
  1. noun
    heater consisting of a series of pipes for circulating steam or hot water to heat rooms or buildings
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    type of:
    heater, warmer
    device that heats water or supplies warmth to a room
  2. noun
    any object that radiates energy
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    radio source
    an object that radiates radio waves
    type of:
    natural object
    an object occurring naturally; not made by man
  3. noun
    a mechanism consisting of a metal honeycomb through which hot fluids circulate; heat is transferred from the fluid through the honeycomb to the airstream that is created either by the motion of the vehicle or by a fan
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    type of:
    device consisting of a piece of machinery; has moving parts that perform some function
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