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English definition of “efficacy”


noun [U] uk   /ˈef.ɪ.kə.si/ formal us  
an ability, especially of a medicine or a method of achieving something, to produce the intended result: They recently ran a series of tests to measure the efficacy of the drug.
Efficient and effective
(Definition of efficacy from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
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