Efficacy meaning

ĕfĭ-kə-sē
Power to produce effects or intended results; effectiveness.
noun
15
3
Power or capacity to produce a desired effect; effectiveness.
noun
13
3
Efficacy is defined as the ability to do what is defined as desired or to be effective at producing a result.

An example of efficacy is when a crime bill is effective at stopping crime.

noun
1
0
(uncountable) Ability to produce a desired amount of a desired effect.
noun
1
1
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Other Word Forms

Noun

Singular:
efficacy
Plural:
efficacies

Origin of efficacy

  • Latin efficācia from efficāx efficāc- efficacious efficacious

    From American Heritage Dictionary of the English Language, 5th Edition

  • From Old French efficace, from Late Latin efficacia (“efficacy”), from Latin efficax (“efficacious”); see efficacious.

    From Wiktionary