Definition of: irradiation

(i·rā′dē·ā′shən) noun
1. The act of irradiating.
2. The state of being irradiated.
3. Rays emitted: the irradiation of a candle.
4. Optics An apparent enlargement of a bright object, when seen against a dark background, due to the fact that the rays of light do not converge accurately to a focus upon the retina.
5. The application, to a person, substance, or object, of any form of radiant energy, for therapeutic, preservative, or other purposes.
6. The amount or intensity of radiation falling on a surface in a given time.
7. Physiol. A diffusion or branching out of afferent nerve impulses or of conditioned reflexes.