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
While Spotify has taken steps in recent years to combat and tamp down streaming fraud, the lawsuit casts doubt on the efficacy of these measures and Spotify’s own incentives to stop fraud.
—
Nancy Dillon, Rolling Stone, 3 Nov. 2025
Scarecrows, plastic owls and snakes, flashy pinwheels, and wind chimes are also of questionable efficacy.
—Andy Wilcox, Better Homes & Gardens, 3 Nov. 2025
The once-daily, oral medication is proven to reduce the frequency and intensity of hot flashes and night sweats, based on clinical studies measuring efficacy at 4 and 12 weeks.
—Marnie Goodfriend, Flow Space, 29 Oct. 2025
If there were, there’d be safety in numbers and a sense of efficacy.
—Michael Shank, MSNBC Newsweek, 27 Oct. 2025
See All Example Sentences for efficacy
Nancy Dillon, Rolling Stone, 3 Nov. 2025
Scarecrows, plastic owls and snakes, flashy pinwheels, and wind chimes are also of questionable efficacy.
—Andy Wilcox, Better Homes & Gardens, 3 Nov. 2025
The once-daily, oral medication is proven to reduce the frequency and intensity of hot flashes and night sweats, based on clinical studies measuring efficacy at 4 and 12 weeks.
—Marnie Goodfriend, Flow Space, 29 Oct. 2025
If there were, there’d be safety in numbers and a sense of efficacy.
—Michael Shank, MSNBC Newsweek, 27 Oct. 2025
See All Example Sentences for efficacy
Recent Examples of Synonyms for efficacy
Noun
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Naysayers on both sides attack, question Newsom's effectiveness Newsom's White House ambitions remain just that, for now.—
Phillip M. Bailey,
USA Today,
3 Nov. 2025
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Worthington said the rhetoric by Republicans in Pennsylvania is helpful, but limited in its effectiveness.—
Will McDuffie,
ABC News,
3 Nov. 2025
Noun
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As technologies improve, conductive systems now achieve anywhere around 85-95% efficiency for both cars and trucks.—
Atharva Gosavi,
Interesting Engineering,
8 Nov. 2025
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Essential, convenience and efficiency always win.—
Orianna Rosa Royle,
Fortune,
7 Nov. 2025
Cite this Entry
“Efficacy.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/efficacy. Accessed 10 Nov. 2025.
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