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 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 These efficacious, natural ingredients include chamomile, California poppy, lemon verbena, linden, magnesium, rosemary and cardamom. Bianca Salonga, Forbes.com, 1 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
  • Without an accountant on staff, one of the most efficient ways to handle these responsibilities is by using accounting software.
    Mia Taylor, CNBC, 27 June 2025
  • Today's dishwashers are much more efficient, using just 3 to 4 gallons of water per load.
    Brandee Gruener, Southern Living, 26 June 2025
Adjective
  • Are commercial grout cleaners more effective than DIY methods?
    Ashlyn Needham, Southern Living, 28 June 2025
  • Unlike generics, they’re not approved by the FDA, a federal agency that verifies whether drugs are safe and effective .
    Queenie Wong, Los Angeles Times, 28 June 2025
Adjective
  • With collaborations like Pink Cookies with THC Design and Skywalker with Rove, plus a party-heavy marketing style, Presidential keeps its image loud, proud and potent. 6.
    Javier Hasse, Forbes.com, 26 June 2025
  • The ending serves as a handy reminder that the zombie movie, more than perhaps any other strain of horror cinema, can be a potent conductor of allegory, metaphor, and polemic.
    Justin Chang, New Yorker, 25 June 2025

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Cite this Entry

“Efficacious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/efficacious. Accessed 2 Jul. 2025.

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