The meaning of EFFICACY is the power to produce a result or effect. How to use efficacy in a sentence.

EFFICACY definition: 1. the ability of something to produce the intended result: 2. how well a particular treatment or…. Learn more.

Efficacy is the ability to perform a task to a satisfactory or expected degree. The word comes from the same roots as effectiveness, and it has often been used synonymously, although in …

EFFICACY definition: the capacity for producing a desired result or effect. See examples of efficacy used in a sentence.

If you talk about the efficacy of something, you are talking about its effectiveness and its ability to do what it is supposed to.

Definition of efficacy noun in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

efficacy (ˈɛfɪkəsɪ) or efficaciousness n the quality of being successful in producing an intended result; effectiveness

Dec 11, 2025 · Efficacy refers to the beneficial effects of a program or policy under optimal conditions of delivery, whereas effectiveness refers to effects of a program or policy under …

efficacy meaning, definition, what is efficacy: the ability of something to produce the ...: Learn more.

There are four meanings listed in OED's entry for the noun efficacy, three of which are labelled obsolete. See ‘Meaning & use’ for definitions, usage, and quotation evidence.