Radiation
Pronunciation : Ra`di*a"tion
Part of Speech : n.
Etymology : [L. radiatio: cf. F. radiation.]
Definition : 1. The act of radiating, or the state of being radiated; emission and diffusion of rays of light; beamy brightness.
2. The shooting forth of anything from a point or surface, like the diverging rays of light; as, the radiation of heat.
Source : Webster's Unabridged Dictionary, 1913