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
Given Southampton’s shape, the space for City to exploit was out wide but their efficacy at doing so was fleeting in the opening 45 minutes.
—
Dan Sheldon, New York Times, 25 Apr. 2026
In a handful of preliminary trials, the drug has shown some efficacy in treating substance use disorders, and the new trial will investigate the drug’s use as a treatment for alcohol use disorder.
—Claire Cameron, Scientific American, 24 Apr. 2026
One of the main reasons peptides have gained such momentum in skincare is their balance of efficacy and gentleness.
—Brianna Peters, Vogue, 22 Apr. 2026
That naturally raised questions, not about whether the laws of time and space had been upended but about the efficacy, and honesty, of the billing systems being used by the firms, the city or both.
—The Editorial Board, Chicago Tribune, 21 Apr. 2026
See All Example Sentences for efficacy
Dan Sheldon, New York Times, 25 Apr. 2026
In a handful of preliminary trials, the drug has shown some efficacy in treating substance use disorders, and the new trial will investigate the drug’s use as a treatment for alcohol use disorder.
—Claire Cameron, Scientific American, 24 Apr. 2026
One of the main reasons peptides have gained such momentum in skincare is their balance of efficacy and gentleness.
—Brianna Peters, Vogue, 22 Apr. 2026
That naturally raised questions, not about whether the laws of time and space had been upended but about the efficacy, and honesty, of the billing systems being used by the firms, the city or both.
—The Editorial Board, Chicago Tribune, 21 Apr. 2026
See All Example Sentences for efficacy
Recent Examples of Synonyms for efficacy
Noun
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By combining cutting-edge protection, mobility, and digital integration, these vehicles are set to play a crucial role in enhancing military effectiveness and safeguarding personnel.—
Prabhat Ranjan Mishra,
Interesting Engineering,
27 Apr. 2026
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Today, affordability is becoming just as important as effectiveness.—
Daniel Fusch,
USA Today,
27 Apr. 2026
Noun
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In most cases, the first few episodes of a series stream for free, and a viewer pays for the rest; profit is further maximized through a staunch commitment to efficiency, often at the expense of labor standards.—
Chang Che,
New Yorker,
25 Apr. 2026
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Far from corporate greed or anticompetitive behavior, competitive discounts driven by volume and supply chain efficiencies fuel free markets, helping families save money on groceries, appliances, TVs, cellphones, computers and cars.—
Stephen Moore,
Boston Herald,
24 Apr. 2026
Cite this Entry
“Efficacy.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/efficacy. Accessed 1 May. 2026.
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