- Act of irradiating, or state of being irradiated. - Illumination; irradiance; brilliancy. - Fig.: Mental light or illumination. - The apparent enlargement of a bright object seen upon
a dark ground, due to the fact that the portions of the retina around
the image are stimulated by the intense light; as when a dark spot on a
white ground appears smaller, or a white spot on a dark ground larger,
than it really is, esp. when a little out of focus.