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 These groups are not going to provide you with anything like efficacious asset protection planning despite their promises. Jay Adkisson, Forbes, 25 Feb. 2025 These efficacious, natural ingredients include chamomile, California poppy, lemon verbena, linden, magnesium, rosemary and cardamom. Bianca Salonga, Forbes.com, 1 Apr. 2025 Oh, that’s right, there’s a measles vaccines that is over 97% efficacious against the measles after two doses are administered, which people have been getting for years. Bruce Y. Lee, Forbes, 15 Mar. 2025 Despite Chief Justice Warren formally writing the opinion to apply exclusively to education, its attack on segregation has—paradoxically—been most efficacious beyond that original context. Justin Driver, The Atlantic, 15 Mar. 2025 See All Example Sentences for efficacious
Recent Examples of Synonyms for efficacious
Adjective
  • The Tigers were efficient on their own end, however, scoring 48 points in the paint.
    Maddie Hartley, Kansas City Star, 15 Mar. 2025
  • The Kings were outscored by 21 points during LaVine’s 36 minutes, despite LaVine shooting an efficient 7-of-13 from the floor.
    Chris Biderman, Sacramento Bee, 15 Mar. 2025
Adjective
  • The Eagles have become so effective at executing the play that some other teams in the NFL want to ban it.
    Quartz Staff, Quartz, 14 Apr. 2025
  • It’s been replaced by a much less effective moment between Joel and his therapist, Gail, played by Catherine O’Hara.
    Erik Kain, Forbes.com, 14 Apr. 2025
Adjective
  • Retrograde means to slow down and the planet’s slow-moving pace makes both the planet and zodiac sign themes all the more potent and impossible to ignore.
    Valerie Mesa, People.com, 15 Mar. 2025
  • One proposal gaining traction is capping THC potency levels to prevent the spread of ultra-potent products.
    Faisal Kutty, Newsweek, 12 Mar. 2025

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Cite this Entry

“Efficacious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/efficacious. Accessed 17 Apr. 2025.

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