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English definition of “effective”

effective

adjective (IN USE)    /ɪˈfek.tɪv/
If a law or rule becomes effective, it starts to be used: The new laws will become effective next month.Affecting and influencing Grammar:Efficient or effective?Efficient and effective are adjectives.See more effectiveness     /-nəs/ noun [U] C1 There are doubts about the effectiveness of the new drug (= how successful it is) in treating the disease.Efficient and effective
(Definition of effective adjective (IN USE) from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)
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