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
  • In some ways, the purpose seems obvious — an efficient way to refine your hand-eye coordination before a big match, like Alcaraz’s showdown with American Taylor Fritz on Friday in the Wimbledon men’s semifinals.
    Rustin Dodd, New York Times, 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
  • Seniors who participate in the AmeriCorps programs, for example, also are involved in different but related programs that may now be less effective because AmeriCorps dollars provided transportation or other services.
    Dan Horn, The Enquirer, 23 July 2025
  • Our tester found the Rubbermaid Reveal to be especially effective for detail cleaning in tight spaces like grout lines and corners.
    Maggie Horton, People.com, 22 July 2025
Adjective
  • Those soft ticket sales suggest that nostalgia isn’t nearly as potent as Sony might have hoped when greenlighting the slasher sequel and reuniting the original 1998 film’s stars, Freddie Prinze Jr. and Jennifer Love Hewitt.
    Rebecca Rubin, Variety, 20 July 2025
  • The moment for me in that scene that’s the most potent is actually not the poster.
    Brian Hiatt, Rolling Stone, 20 July 2025

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Cite this Entry

“Efficacious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/efficacious. Accessed 25 Jul. 2025.

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