Hallucination
HALLUCINA'TION, noun [Latin hallucinatio, from hallucinor, to blunder.]
1. Error; blunder; mistake. [Little Used.]
2. In medicine, faulty sense [dysaesthesia, ] or erroneous imagination. Hallucinations of the senses, arise from some defect in the organs of sense, or from some unusual circumstances attending the object, as when it is seen by moonlight; and they are sometimes symptoms of general disease, as in fevers. Maniacal hallucinations arise from some imaginary or mistaken idea. Similar hallucinations occur in revery.