delusion

/dɪˈluʒɪn/

/dɪˈluʒən/

Other forms: delusions

A delusion is a belief that has no evidence in fact — a complete illusion. The cook at the hot dog stand who thinks he is the best chef in the world? That opinion is definitely a delusion.

The noun delusion is often used in the phrase delusions of grandeur, which expresses the belief that unattainable goals are well within reach, like a terrible actress's delusions of grandeur that she won't just land her first role in a movie, it also will make her an Academy Award winner. Delusions like that can be amusing for onlookers, but other kinds of delusions are not, like those suffered by the mentally ill. Their delusions can remove them from reality, making it hard to function.

Definitions of delusion

1. noun

   a mistaken or unfounded opinion or idea
   “he has delusions of competence”

   synonyms: hallucination

   types:

   disorientation, freak out

   a wild delusion (especially one induced by a hallucinogenic drug)

   type of:

   misconception

   an incorrect conception
2. noun

   the act of deluding; deception by creating illusory ideas
   synonyms: head game, illusion

   type of:

   deceit, deception, dissembling, dissimulation

   the act of deceiving
3. noun

   (psychology) an erroneous belief that is held in the face of evidence to the contrary
   synonyms: psychotic belief

   types:

   delusions of grandeur

   a delusion (common in paranoia) that you are much greater and more powerful and influential than you really are

   delusions of persecution

   a delusion (common in paranoia) that others are out to get you and frustrate and embarrass you or inflict suffering on you; a complicated conspiracy is frequently imagined

   hallucination

   illusory perception; a common symptom of severe mental disorder

   nihilism, nihilistic delusion

   the delusion that things (or everything, including the self) do not exist; a sense that everything is unreal

   somatic delusion

   a delusion concerning the body image or parts of the body

   zoanthropy

   the delusion that you have assumed the form of an animal

   acousma, auditory hallucination

   illusory auditory perception of strange nonverbal sounds

   pseudohallucination

   an image vivid enough to be a hallucination but recognized as unreal

   visual hallucination

   illusory visual perception

   type of:

   mental condition, mental state, psychological condition, psychological state

   (psychology) a mental condition in which the qualities of a state are relatively constant even though the state itself may be dynamic