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a. The act or process of deluding.
b. The state of being deluded.
a. A false belief or opinion: labored under the delusion that success was at hand.
b. Psychiatry A false belief or perception that is a manifestation of a mental illness: delusions of persecution.

[Middle English delusioun, from Latin dēlūsiō, dēlūsiōn-, from dēlūsus, past participle of dēlūdere, to delude; see delude.]

de·lu′sion·al adj.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Adj.1.delusional - suffering from or characterized by delusions
psychoneurotic, neurotic - affected with emotional disorder
References in periodicals archive ?
If allegations are unsubstantiated, interview the patient, watch for signs of delusional or factitious disorder or malingering, and treat accordingly.
He never mentioned being delusional at any time before or after the shooting, and there was no evidence that he was.
But her loss takes on a truly nightmarish quality when Sam disappears from those photos and tapes and her husband (Anthony Edwards) claims they never had a child and that she is delusional.
Our colleagues in neuroscience have been trying to find a brain defect that may be the "cause" of delusion or delusional ideation and have been largely inattentive to the potential for delusion in normal human development.
A romantic belief persists that the only kinds of sexual, romantic, and aesthetic pursuits of real interest are those fueled by delusional manias.
Nicky Morgan is naive and delusional to believe otherwise.
She sang: "You're delusional, boy, you're losing your mind.
Wong likes to speak of how his employees enjoy their life in the compound, but this delusional man becomes most animated when speaking of the punishments he metes out to keep his workers churning out the requisite tons of beads per day.
Our interest in this question is grounded in a decade and a half of study of delusional disorder.
If they're banking on League of Ireland football for a living they're delusional.
The Armed Forces of the Philippines is delusional in saying that it will finish off the New People's Army or in Armed Forces of the Philippines chief Rey Guerrero's reprise, reduce the NPA 'by half' in the middle of 2018,' the CPP said in a statement.
Sarah Reese looks very uncomfortable when she encounters a delusional patient.