heat sink

noun

1. Thermodynamics. any environment or medium that absorbs heat.
2. Also heat·sink. Electronics. a metallic heat exchanger designed to absorb and dissipate excess heat from one of the devices, as a transistor or resistor, in a circuit.

noun

1. a metal plate specially designed to conduct and radiate heat from an electrical component
2. a layer of material placed within the outer skin of high-speed aircraft to absorb heat

1. A protective device that absorbs and dissipates the excess heat generated by a system.
2. An environment capable of absorbing heat from substances within it (and with which it is in thermal contact) without an appreciable change in its own temperature and without a change in its own phase.