1. any object that radiates energy (Freq. 1) • Derivationally related forms: radiate • Hypernyms: natural object • Hyponyms: radio source 2. heater consisting of a series of pipes for circulating steam or hot water to heat rooms or buildings • Hypernyms: heater, warmer • Part Holonyms: heating system, heating plant, heating, heat 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 • Hypernyms: mechanism • Part Holonyms: cooling system, engine cooling system • Part Meronyms: radiator cap
