Definitions from Black's Law Dictionary: 2nd Edition and Ballentine's Law Dictionary as are available for each term in each dictionary.
  • Ballentine's Law Dictionary

    That which one believes he sees, but really does not.

  • Black's Law Dictionary: 2nd Edition

    In medical jurisprudence. An image or impression in the mind, excited by some external object addressing itself to one or more of the senses, but which, instead of corresponding with the reality, is perverted, distorted or wholly mistaken, the error being attributable to the imagination of the observer, not to any defect in the organs of sense. See Hallucination, and see "Delusion," under Insanity.