Emily Dickinson Lexicon

HAL-LU-CIN-A'TION, n. [L. hallucinatio, from hallucinor, to blunder.]

1. Error; blunder; mistake. [Little used.] Addison.
2. In medicine, faulty sense [dysæsthesia] 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. Darwin. Parr.