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English definition of “side effect”

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side effect

noun [C] uk   us  
C1 an unpleasant effect of a drug that happens in addition to the main effect: Does this drug have any side effects?C2 an unexpected result of a situation: A side effect of the new law is that fewer people will take out insurance.
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(Definition of side effect from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
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