Irradiance
Pronunciation : Ir*ra"di*ance, Ir*ra"di*an*cy
Part of Speech : n.
Etymology : [From Irradiant.]
Definition : 1. The act of irradiating; emission of rays of light.
2. That which irradiates or is irradiated; luster; splendor; irradiation; brilliancy. Milton.
Source : Webster's Unabridged Dictionary, 1913