Definition of illusion in English:


Line breaks: il¦lu|sion
Pronunciation: /ɪˈl(j)uːʒ(ə)n



be under the illusion that

Believe mistakenly that: the world is under the illusion that the original painting still hangs in the Winter Palace
More example sentences
  • ‘No one should be under the illusion that because a plan exists in one form today that it will be that way forever,’ he said.
  • The Popular Unity's supporters were under the illusion that once in power it would fulfil the promise of profound political and socio-economic change.
  • Progressives have been under the illusion that if only people understood the facts, we'd be fine.

be under no illusion (or illusions)

Be fully aware of the true state of affairs.
More example sentences
  • She says she has been greatly impressed with the efficiency of the Dundee operation but is under no illusions about the challenges facing a factory on the northern fringes of Europe.
  • But I'm under no illusions, it could be taken away at any point, so I just grab it with both hands.
  • The 35-year-old is under no illusions about his situation.



More example sentences
  • The illusional architecture was then painted by Orazio's associate, Agostino Tassi, a master of perspective, who had been engaged to teach that art to Artemisia.
  • Anyway, we know the extent of Pennyn's powers is at least illusional.


More example sentences
  • Liberties would be discarded to seek illusionary security; commerce would grind to a halt under the burden of regulation and continual emergency.
  • Dreams pervade the play, giving it an illusionary quality and heightening the sense of dark hilarity that frequently has the audience hysterical with laughter.
  • The momentary pain of a sting gives way to an illusionary floating feeling that lasts six to eight hours.


Middle English (in the sense 'deceiving, deception'): via Old French from Latin illusio(n-), from illudere 'to mock', from in- 'against' + ludere 'play'.

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