a mistaken or misleading opinion, idea, belief, etc a belief held subjectively in the face of objective evidence to the contrary, that is resistant to all reason
See also illusion, hallucinationthe act of deluding or state of being deluded
WordReference Random House Learner's Dictionary of American English © 2026
de•lu•sion /dɪˈluʒən/USA pronunciation
n.
WordReference Random House Unabridged Dictionary of American English © 2026- the state of being deluded:[uncountable]suffering from delusion.
- Psychiatry a false belief or opinion:[countable]delusions of grandeur.
- See illusion.
de•lu•sion
(di lo̅o̅′zhən),USA pronunciation n.
de•lu′sion•al, de•lu′sion•ar′y, adj.
- an act or instance of deluding.
- the state of being deluded.
- Psychiatrya false belief or opinion:delusions of grandeur.
- Psychiatrya fixed false belief that is resistant to reason or confrontation with actual fact:a paranoid delusion.
- Latin dēlūsiōn- (stem of dēlūsiō), equivalent. to dēlūs(us) (past participle of dēlūdere; see delude) + -iōn- -ion
- late Middle English 1375–1425
- 1.See corresponding entry in Unabridged deception. See illusion.
Collins Concise English Dictionary © HarperCollins Publishers::
'delusion' also found in these entries (note: many are not synonyms or translations):
Buddhism
- Dawkins
- aberration
- bubble
- chimera
- delusive
- fallacy
- folie de grandeur
- hallucination
- illusion
- lycanthropy
- mare's-nest
- megalomania
- nirvana
- self-delusion