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illusion

US //ˌɪˈɫuʒən// UK //ɪlˈuːʒən// il·lu·sion
  1. 1 deceptive appearance (n.)
    B2 Upper Intermediate

    something that looks or feels different from what it really is.

    an instance of a sensory perception that causes a false interpretation of physical reality.

    Example

    The mirrors in the small hallway create the illusion of a much larger space.

    Example

    The desert heat created a shimmering optical illusion on the horizon, making the dry road appear as though it were covered in water.

  2. 2 false belief (n.)
    B2 Upper Intermediate

    a false idea or belief that you think is true.

    a persistent false belief or misconception regarding a situation or person.

    Example

    He was under the illusion that the job would be easy, but it was very hard.

    Example

    The administration maintained the illusion of progress despite mounting evidence that the project was failing to meet its primary objectives.

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  1. 3 magician's trick (n.)
    B2 Upper Intermediate Theatre

    a clever trick performed by a magician to surprise an audience.

    a professional trick or effect performed by an entertainer to deceive the eyes of an audience.

    Example

    The magician performed a famous illusion where he appeared to float in the air.

    Example

    The stage production relied on sophisticated lighting and hidden mirrors to execute the complex illusion of the protagonist vanishing mid-sentence.

Origin

From Old French illusion, from Latin illūsiō, from illūdere, from in- (“at, upon”) + lūdere (“to play, mock, trick”). Displaced native Old English dwimmer.

Idioms1 entry

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