Synonym Chooser

How does the adjective efficacious contrast with its synonyms?

Some common synonyms of efficacious are effective, effectual, and efficient. While all these words mean "producing or capable of producing a result," efficacious suggests possession of a special quality or virtue that gives effective power.

a detergent that is efficacious in removing grease

When is effective a more appropriate choice than efficacious?

In some situations, the words effective and efficacious are roughly equivalent. However, effective stresses the actual production of or the power to produce an effect.

an effective rebuttal

When would effectual be a good substitute for efficacious?

Although the words effectual and efficacious have much in common, effectual suggests the accomplishment of a desired result especially as viewed after the fact.

the measures to stop the pilfering proved effectual

When can efficient be used instead of efficacious?

While the synonyms efficient and efficacious are close in meaning, 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

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Recent Examples of efficacious Rhode is dedicated to making products based in science and great formulation, simplifying many of the mysteries and complex narratives behind efficacious skincare. Jason Pham, StyleCaster, 29 May 2025 If price controls are adopted in the U.S., then patients living with Alzheimer’s disease, pancreatic cancer, or muscular dystrophy may end up waiting in vain for efficacious treatments. Wayne Winegarden, Forbes.com, 4 May 2025 Consequently, these controls exacerbate the tension between patients who have access to safe and efficacious medicines and patients living with untreated or poorly treated conditions. Wayne Winegarden, Forbes.com, 20 Apr. 2025 Thorne is also rigorously tested and has worked with independent researchers from places like Mayo Clinic and the National Institutes of Health, to ensure its products are high-performance, safe, and efficacious. Vogue, 30 Mar. 2025 See All Example Sentences for efficacious
Recent Examples of Synonyms for efficacious
Adjective
  • By having the facility on site, SpaceX hopes to make the delivery of those gases more efficient by eliminating the need to have dozens of trucks deliver them from Brownsville.
    ArsTechnica, ArsTechnica, 11 July 2025
  • Organizations that focus on integrating their systems may see faster, more efficient reporting, centralized information management and a comprehensive view of progress toward goals.
    Cynthia Tee, Forbes.com, 11 July 2025
Adjective
  • Using effective property management practices and adopting technology can help reach these objectives.
    Nathan Levinson, Forbes.com, 10 July 2025
  • The United States plans to bring back a somewhat shocking, but very effective, campaign to fight a flesh-eating parasitic fly that's been sighted in Mexico.
    Elizabeth Weise, USA Today, 10 July 2025
Adjective
  • Much like its approach to skincare, Korean hair care is rooted in a philosophy of prevention, nourishment, and layering lightweight yet potent formulas.
    Conçetta Ciarlo, Vogue, 8 July 2025
  • That’s a potent incentive to take your vacation and come back to work energized.
    Harry Kraemer, Forbes.com, 8 July 2025

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Cite this Entry

“Efficacious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/efficacious. Accessed 20 Jul. 2025.

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