Main Entry:
ir·ra·di·a·tion Pronunciation:
ir-"Ad-E-'A-sh&n Function:
noun 1 a : the radiation of a physiologicallyactive agent from a point of origin within the body;
especially : the spread of a nervous impulse beyond the usual conduction path
b : apparent enlargement of a lightor bright object or surface when displayed against a dark background
2 a : exposure to radiation (as ultraviolet light, X rays, or alpha particles)
b : applicationof radiation (as X rays or gamma rays) especially for therapeutic purposes
3 : IRRADIANCE