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

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 pharmacology a …

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

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.

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

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

Jan 20, 2026 · 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 more real-world …

Collins Concise English Dictionary © HarperCollins Publishers:: efficacy /ˈɛfɪkəsɪ/, efficaciousness /ˌɛfɪˈkeɪʃəsnəs/ n the quality of being successful in producing an intended result; effectiveness …

It signifies the degree to which a particular action, process, or solution is successful in achieving its intended purpose or goal. Efficacy is often used in discussions related to medicine, therapies, …