delusional

[ dih-loo-zhuh-nl ]

/ dɪˈlu ʒə nl /

adjective

having false or unrealistic beliefs or opinions: Senators who think they will get agreement on a comprehensive tax bill are delusional.

Psychiatry. maintaining fixed false beliefs even when confronted with facts, usually as a result of mental illness: He was so delusional and paranoid that he thought everybody was conspiring against him.

Nearby words

deluge, delusion, delusion of grandeur, delusion of negation, delusion of persecution, delusional, delusive, delusively, delusory, delusterant, delustering

Sometimes de·lu·sion·ar·y.

Definition for delusionary (2 of 2)

delusion

[ dih-loo-zhuhn ]

/ dɪˈlu ʒən /

noun

an act or instance of deluding.

the state of being deluded.

a false belief or opinion: delusions of grandeur.

Psychiatry. a fixed false belief that is resistant to reason or confrontation with actual fact: a paranoid delusion.

Origin of delusion

1375–1425; late Middle English < Latin dēlūsiōn- (stem of dēlūsiō), equivalent to dēlūs(us) (past participle of dēlūdere; see delude) + -iōn- -ion

SYNONYMS FOR delusion

1 deception. See illusion.

Related formsde·lu·sion·al, de·lu·sion·ar·y, adjectivepre·de·lu·sion, noun

Can be confusedallusion delusion elusion hallucination illusion (see synonym study at illusion)

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for delusionary

delusion

/ (dɪˈluːʒən) /

noun

a mistaken or misleading opinion, idea, belief, etche has delusions of grandeur

psychiatry a belief held in the face of evidence to the contrary, that is resistant to all reasonSee also illusion, hallucination

the act of deluding or state of being deluded

Derived Forms

delusional, adjectivedelusive, adjectivedelusively, adverbdelusiveness, noun

delusory (dɪˈluːsərɪ), adjective

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for delusionary (1 of 2)

delusional

adj.

1871, from delusion + -al (1).

Word Origin and History for delusionary (1 of 2)

delusion

"act of misleading someone," early 15c.; as a form of mental derangement, 1550s, from Latin delusionem (nominative delusio) "a deceiving," noun of action from past participle stem of deludere (see delude).

Technically, delusion is a belief that, though false, has been surrendered to and accepted by the whole mind as a truth; illusion is an impression that, though false, is entertained provisionally on the recommendation of the senses or the imagination, but awaits full acceptance and may not influence action. Delusions of grandeur, the exact phrase, is recorded from 1840, though the two words were in close association for some time before that.

Medicine definitions for delusionary

delusion

[ dĭ-lōō′zhən ]

n.

A false belief strongly held in spite of invalidating evidence, especially as a symptom of mental illness.

Related formsde•lu′sion•al adj.

Science definitions for delusionary

delusion

[ dĭ-lōō′zhən ]

A false belief or perception strongly held in spite of invalidating evidence, especially as a symptom of mental illness, as in schizophrenia.

Culture definitions for delusionary

delusion

A false belief held despite strong evidence against it; self-deception. Delusions are common in some forms of psychosis. Because of his delusions, the literary character Don Quixote attacks a windmill, thinking it is a giant.