1. A heating device consisting of a series of connected pipes, typically inside an upright metal structure, through which steam or hot water is circulated so as to radiate heat into the surrounding space.
2. A cooling device, as in automotive engines, through which water or other fluids circulate as a coolant.
3. physics A body that emits radiation.
4. A transmitting antenna.

1. anything which radiates or emits rays.
2. A device that lowers engine coolant temperature by conducting heat to the air, through metal fins.
3. A finned metal fixture that carries hot water or steam in order to heat a room.
4. A type of antenna.

1. that which radiates or emits rays, whether of light or heat; especially, that part of a heating apparatus from which the heat is radiated or diffused.
2. any of various devices for cooling an internal substance by radiation, as a system of rings on a gun barrel for cooling it, or a nest of tubes with large radiating surface for cooling circulating water, as in an automobile.
3. an oscillator.

1. anything which radiates; a body or substance from which rays of heat emanate or radiate.
2. A part of a heating apparatus designed to communicate heat to a room, chiefly by convection, but partly, in some cases, by radiation.
3. same as cooler, 2 .
4. in the transmission of electric waves, as in wireless telegraphy, an apparatus for the emission of electric oscillations; a form of oscillator.

1. any object that radiates energy
2. heater consisting of a series of pipes for circulating steam or hot water to heat rooms or buildings
3. 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