Definition

1. Noun:
   • A false belief or impression: A belief or impression that is firmly held despite being contradicted by reality or rational argument.
   • The state of being deluded: The act of deluding or the condition of being misled or deceived.
   • A symptom of mental disorder: In psychology and psychiatry, a fixed, false belief that is resistant to reason or confrontation with actual fact, often occurring as a symptom of conditions like schizophrenia.

Examples of Usage

• As a false belief:
  • He suffers from the delusion that he is a famous historical figure.
  • She was under the delusion that her work was universally admired.
• As a state of deception:
  • The scheme was based on fraud and delusion.
• In a clinical/psychological context:
  • The patient's paranoid delusions made treatment difficult.

Advanced Usage

• "Delusion of grandeur": A false belief in one's own importance, power, knowledge, or identity, often to a grandiose extent.
  • His claim to be the secret king was a clear delusion of grandeur.
• "Delusion of persecution": A false and persistent belief that one is being threatened, harmed, or conspired against.
  • The individual's delusion of persecution led them to distrust everyone.

Variants and Related Words

• Delude (verb): To mislead the mind or judgment of; to deceive.
  • He deluded himself into thinking he could succeed without effort.
• Delusional (adjective): Characterized by or holding false beliefs or impressions.
  • His plans were dismissed as delusional.
• Delusive (adjective): Tending to delude; misleading; deceptive.
  • The promise of quick wealth was a delusive fantasy.

Synonyms

• Illusion: A false idea or belief, often one that is more general or perceptual.
• Misconception: A view or opinion that is incorrect because it is based on faulty thinking or understanding.
• Hallucination (in some contexts, particularly regarding sensory experiences): A perception of something that is not present.

Related Phrases

• To be under a delusion / to labour under a delusion: To hold a false belief.
  • He is labouring under the delusion that he can change their minds.
• A cruel delusion: A particularly painful or harsh false hope or belief.
  • The hope of a peaceful resolution proved to be a cruel delusion.

Idioms and Fixed Expressions

• Delusions of adequacy: (Often humorous) A false belief in one's own sufficient competence, typically implying the competence is, in fact, lacking.
  • The manager's delusions of adequacy were a constant source of team frustration.

Noun

1. the act of deluding; deception by creating illusory ideas
2. a mistaken or unfounded opinion or idea
   • he has delusions of competence
   • his dreams of vast wealth are a hallucination
3. (psychology) an erroneous belief that is held in the face of evidence to the contrary