Definitions

from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. The act of exposing or the condition of being exposed to radiation.
  • n. The use or application of ionizing radiation, especially in medical treatment and for the sterilization or preservation of food.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. An act of irradiating, or state of being irradiated.
  • n. illumination; irradiance; brilliance.
  • n. figurative: mental light or illumination.
  • n. 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, especially when a little out of focus.
  • n. a process of sterilisation whereby radiation is passed through a bag containing food, utensils, etc., to sterilise the contents.

from the GNU version of the Collaborative International Dictionary of English

  • n. Act of irradiating, or state of being irradiated.
  • n. Illumination; irradiance; brilliancy.
  • n. Fig.: Mental light or illumination.
  • n. 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.

from The Century Dictionary and Cyclopedia

  • n. The act of irradiating or emitting beams of light; illumination; brightness emitted; enlightenment.
  • n. In physics, the phenomenon of the apparent enlargement of an object strongly illuminated, when seen against a dark ground.
  • n. In neurology, the diffusion of a nervous impulse to parts outside the normal path of conduction.
  • n. In therapeutics, subjection to the influence of X-rays or other form of radioactivity.
  • n. In anatomy, the disposition of fibrous or other structures in stellate form.
  • n. In chem., exposure to radiant light: as, some substances are said to phosphoresce by irradiation.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. (physiology) the spread of sensory neural impulses in the cortex
  • n. (medicine) the treatment of disease (especially cancer) by exposure to a radioactive substance
  • n. a column of light (as from a beacon)
  • n. the condition of being exposed to radiation
  • n. the apparent enlargement of a bright object when viewed against a dark background
  • n. (Pavolvian conditioning) the elicitation of a conditioned response by stimulation similar but not identical to the original stimulus

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