Ir-rā'di-ā'tion, n.

n. [Fr. irradiation, Sp. irradiacion, It. irradiazione.]

1. The act of emitting beams of light.
2. That which is irradiated; illumination; irradiance. W. Scott.
3. (Opt.) An apparent enlargement of brilliant objects beyond their proper bounds, in consequence of the vivid impression of light on the eye.