as in effectiveness
the power to produce a desired result
questioned the efficacy of the alarms in actually preventing auto theft
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Recent Examples of efficacy
It is expected to produce next-generation weight-loss therapies, including retatrutide , an injectable medication with higher weight-loss efficacy than Zepbound, its commercially available obesity treatment.
—
Jeff Marks, CNBC, 30 Jan. 2026
How exactly districts plan to monitor the efficacy of AI in the classroom largely remains to be seen.
—Grace Tucker, Cincinnati Enquirer, 29 Jan. 2026
That, along with her incredible skin, is truly a testament to their efficacy.
—Margaux Anbouba, Vogue, 29 Jan. 2026
Phase 1 human clinical trials showed it was well tolerated, and Bakshi says early results in Phase 2, which is focused on both safety and efficacy, are promising.
—Ana Castelain, Bloomberg, 28 Jan. 2026
See All Example Sentences for efficacy
Jeff Marks, CNBC, 30 Jan. 2026
How exactly districts plan to monitor the efficacy of AI in the classroom largely remains to be seen.
—Grace Tucker, Cincinnati Enquirer, 29 Jan. 2026
That, along with her incredible skin, is truly a testament to their efficacy.
—Margaux Anbouba, Vogue, 29 Jan. 2026
Phase 1 human clinical trials showed it was well tolerated, and Bakshi says early results in Phase 2, which is focused on both safety and efficacy, are promising.
—Ana Castelain, Bloomberg, 28 Jan. 2026
See All Example Sentences for efficacy
Recent Examples of Synonyms for efficacy
Noun
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Mixing grapefruit, whether as a juice or in a dietary supplement, with some medications can disrupt how the drugs are processed in your body, potentially causing dangerous side effects or loss of effectiveness.—
Ross Phan,
Verywell Health,
9 Feb. 2026
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Psyduck, one of the main Pokémon used by Misty in the series, was a water-type who could use powerful psychic moves, but the timing and effectiveness of its abilities was disrupted by its constant headaches.—
Jordan Moreau,
Variety,
9 Feb. 2026
Noun
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Morgan Stanley also came to the defense of the large-cap banks, saying the banks are AI beneficiaries since AI tools should improve operational efficiencies and drive productivity gains.—
Paulina Likos,
CNBC,
13 Feb. 2026
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The leather of both has softened with age, but there are no cracks in their surfaces, the insulation is still lofty enough for thermal efficiency, and neither the Give’r nor the Kinco’s extended cuffs have stretched beyond normal wear.—
Maggie Slepian,
Outside,
13 Feb. 2026
Cite this Entry
“Efficacy.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/efficacy. Accessed 14 Feb. 2026.
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