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English definition of “side effect”

side effect

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