Illusory perception; a common symptom of severe mental disorder.

Dutch: hallucinatie

A mistaken or unfounded opinion or idea:
— His dreams of vast wealth are a hallucination.

synonym: delusion.

Roget 495: error, fallacy; misconception, misapprehension, misstanding^†, misunderstanding; inexactness etc. adj.; laxity; misconstruction etc. (misinterpretation) 523; miscomputation etc. (misjudgment) 481; non sequitur etc. 477; mis-statement, mis-report; mumpsimus^†.    mistake; miss, fault, blunder, quiproquo, cross purposes, oversight, misprint, erratum, corrigendum, slip, blot, flaw, loose thread; trip, stumble etc. (failure) 732; botchery etc. (want of skill) 699^†; slip of the tongue, slip of the lip, Freudian slip; slip of the pen; lapsus linguae [Lat.], clerical error; bull etc. (absurdity) 497; haplography^†.    illusion, delusion; snare; false impression, false idea; bubble; self-decit, self-deception; mists of error.    heresy etc. (heterodoxy) 984; hallucination etc. (insanity) 503; false light etc. (fallacy of vision) 443; dream etc. (fancy) 515; fable etc. (untruth) 546; bias etc. (misjudgment) 481; misleading etc. v.. ... show more

Roget 503: disordered reason, disordered intellect; diseased mind, unsound mind, abnormal mind; derangement, unsoundness; psychosis; neurosis; cognitive disorder; affective disorder^†.    insanity, lunacy; madness etc. adj.; mania, rabies, furor, mental alienation, aberration; paranoia, schizophrenia; dementation^†, dementia, demency^†; phrenitis^†, phrensy^†, frenzy, raving, incoherence, wandering, delirium, calenture of the brain^†; delusion, hallucination; lycanthropy^†; brain storm^†.    vertigo, dizziness, swimming; sunstroke, coup de soleil [Fr.], siriasis^†.    fanaticism, infatuation, craze; oddity, eccentricity, twist, monomania (caprice) 608; kleptodipsomania^†; hypochondriasis [Med.] etc. (low spirits) 837; melancholia, depression, clinical depression, severe depression; hysteria; amentia^†.    screw loose, tile loose, slate loose; bee in one's bonnet, rats in the upper story.    dotage etc. (imbecility) 499.    ... show more

Dutch: chimère, drogbeeld, fantasma, hallucinatie, hersenschim, hersenspinsel, illusie, spooksel, waan, waandenkbeeld, waanidee, waanvoorstelling, zinsbegoocheling ... show more
Polish: iluzja

An object perceived during a hallucinatory episode.

Polish: omam