Origin of optical illusion

First recorded in 1785–95

Definition for optical illusion (2 of 2)

illusion
[ ih-loo-zhuhn ]
/ ɪˈlu ʒən /

noun

something that deceives by producing a false or misleading impression of reality.
the state or condition of being deceived; misapprehension.
an instance of being deceived.
Psychology. a perception, as of visual stimuli (optical illusion), that represents what is perceived in a way different from the way it is in reality.
a very thin, delicate tulle of silk or nylon having a cobwebbed appearance, for trimmings, veilings, and the like.
Obsolete. the act of deceiving; deception; delusion.

Origin of illusion

1300–50; Middle English < Latin illūsiōn- (stem of illūsiō) irony, mocking, equivalent to illūs(us) past participle of illūdere to mock, ridicule ( il- il-1 + lūd- play (see ludicrous) + -tus past participle suffix, with dt > s) + -iōn- -ion

SYNONYMS FOR illusion

1 aberration, fantasy, chimera. illusion, hallucination, delusion refer to false perceptions or ideas. An illusion is a false mental image produced by misinterpretation of things that actually exist: A mirage is an illusion produced by reflection of light against the sky. A hallucination is a perception of a thing or quality that has no physical counterpart: Under the influence of LSD, Terry had hallucinations that the living-room floor was rippling. A delusion is a persistent false belief: A paranoiac has delusions of persecution.

OTHER WORDS FROM illusion

il·lu·sioned, adjective

WORDS THAT MAY BE CONFUSED WITH illusion

allusion delusion elusion hallucination illusion (see synonym study at the current entry)

Example sentences from the Web for optical illusion

British Dictionary definitions for optical illusion (1 of 2)

optical illusion

noun

an object causing a false visual impression
an instance of deception by such an object

British Dictionary definitions for optical illusion (2 of 2)

illusion
/ (ɪˈluːʒən) /

noun

a false appearance or deceptive impression of reality the mirror gives an illusion of depth
a false or misleading perception or belief; delusion he has the illusion that he is really clever
psychol a perception that is not true to reality, having been altered subjectively in some way in the mind of the perceiver See also hallucination
a very fine gauze or tulle used for trimmings, veils, etc

Derived forms of illusion

illusionary or illusional, adjective illusioned, adjective

Word Origin for illusion

C14: from Latin illūsiō deceit, from illūdere; see illude

Medical definitions for optical illusion

illusion
[ ĭ-lōōzhən ]

n.

An erroneous perception of reality.
An erroneous concept or belief.
The condition of being deceived by a false perception or belief.
Something, such as a fantastic plan or desire, that causes an erroneous belief or perception.

Other words from illusion

il•lusion•al null adj.