radiation nedir? radiation nedir? The act or process of radiating: the radiation of heat and light from a fire. Physics Emission and propagation and emission of energy in the form of rays or waves.Physics Energy radiated or transmitted as rays, waves, in the form of particles.Physics A stream of particles or electromagnetic waves emitted by the atoms and molecules of a radioactive substance as a result of nuclear decay.The act of exposing or the condition of being exposed to such energy.The application of such energy, as in medical treatment.Anatomy Radial arrangement of parts, as of a group of nerve fibers connecting different areas of the brain.The spread of a group of organisms into new habitats.Adaptive radiation.