delusion

 
Pronunciation: /dɪˈl(j)uːʒ(ə)n/

noun

  • an idiosyncratic belief or impression maintained despite being contradicted by reality or rational argument, typically as a symptom of mental disorder: the delusion of being watched
  • [mass noun] the action of deluding or the state of being deluded: what a capacity television has for delusion

Phrases

delusions of grandeur

a false impression of one’s own importance.

Derivatives

delusional

adjective

Origin:

late Middle English (in the sense 'act of deluding or of being deluded'): from late Latin delusio(n-), from the verb deludere (see delude)