radiation of heat and light

ra·di·a·tion (rd-shn)

n.

1. The act or process of radiating: the radiation of heat and light from a fire.

2. Physics

a. Emission and propagation and emission of energy in the form of rays or waves.

b. Energy radiated or transmitted as rays, waves, in the form of particles.

c. A stream of particles or electromagnetic waves emitted by the atoms and molecules of a radioactive substance as a result of nuclear decay.