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fast one

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noun Informal.
a shrewd action, especially when unscrupulous or dishonest; an unfair trick, deceitful practice, dishonest dealing, etc.: He pulled a fast one on me by paying me with a worthless check.
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Origin of fast one

An Americanism dating back to 1920–25
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

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