Radiator/ˈreɪdieɪtər/ Definition 1 of 2Pro Tip 1/3Interior Heating Highlights the purpose of a room radiator for warmth. Turn on the radiator, so the room gets toasty. Pro Tip 2/3Common Location Describes typical placement of room radiators in buildings. The radiator is usually under the window. Pro Tip 3/3Physical Contact Advises caution about touching as radiators can get hot. Be careful not to touch the radiator; it's scalding!