efficacious

adjective ef·fi·ca·cious \ ˌe-fə-ˈkā-shəs \

Definition of efficacious

:having the power to produce a desired effect
  • an efficacious remedy

efficaciously

adverb

efficaciousness

noun

efficacious was our Word of the Day on 06/16/2011. Hear the podcast!

Examples of efficacious in a Sentence

  1. taking a cookie break while studying is one of the most efficacious ways of rejuvenating the mind that I have ever discovered

Recent Examples of efficacious from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'efficacious.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of efficacious

Latin efficac-, efficax, from efficere

Synonym Discussion of efficacious

effective, effectual, efficient, efficacious mean producing or capable of producing a result. effective stresses the actual production of or the power to produce an effect.
    • an effective rebuttal
effectual suggests the accomplishment of a desired result especially as viewed after the fact.
    • the measures to stop the pilfering proved effectual
efficient suggests an acting or a potential for action or use in such a way as to avoid loss or waste of energy in effecting, producing, or functioning.
    • an efficient small car
efficacious suggests possession of a special quality or virtue that gives effective power.
    • a detergent that is efficacious in removing grease

EFFICACIOUS Defined for English Language Learners

efficacious

adjective

Definition of efficacious for English Language Learners

  • : having the power to produce a desired result or effect



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