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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Example Sentences
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Recent Examples of efficacy
The largest study enrolled just 80 children, and the other, smaller trials had design flaws that cast doubt on any hints of efficacy.
—
Lisa Jarvis, Mercury News, 25 Sep. 2025
The study tested the efficacy of four bite-resistant wetsuit materials–Aqua Armour, Shark Stop, ActionTX-S, and Brewster material.
—Laura Baisas, Popular Science, 24 Sep. 2025
The ordeal raised questions about the efficacy of the Omnilert system.
—Rachel Wegner, Nashville Tennessean, 24 Sep. 2025
As in the previous test, IIHS researchers tested seat-belt efficacy through simulations of a head-on collision.
—Jackie Charniga, Freep.com, 21 Sep. 2025
See All Example Sentences for efficacy
Lisa Jarvis, Mercury News, 25 Sep. 2025
The study tested the efficacy of four bite-resistant wetsuit materials–Aqua Armour, Shark Stop, ActionTX-S, and Brewster material.
—Laura Baisas, Popular Science, 24 Sep. 2025
The ordeal raised questions about the efficacy of the Omnilert system.
—Rachel Wegner, Nashville Tennessean, 24 Sep. 2025
As in the previous test, IIHS researchers tested seat-belt efficacy through simulations of a head-on collision.
—Jackie Charniga, Freep.com, 21 Sep. 2025
See All Example Sentences for efficacy
Recent Examples of Synonyms for efficacy
Noun
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There’s no denying the cost-effectiveness of investing in a high-quality luggage set, so this seasonal sale is the time to score the Coolife Luggage 4-piece Set while bags are only $34 apiece.—
Merrell Readman,
Travel + Leisure,
6 Oct. 2025
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Young children have to use spacers, holding chambers that allow the patient to breathe in the medication slowly so more of it reaches the lungs, and a spacer would hinder a dry-powder inhaler’s effectiveness.—
Jen Christensen,
CNN Money,
6 Oct. 2025
Noun
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Coming in just under $100,, this air purifier has garnered the love and attention of 13,000 reviewers who praise this model for its efficiency and aesthetics.—
Julia Harrison,
Architectural Digest,
3 Oct. 2025
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Margin-sensitivity refers to being focused on fees and net cost efficiency — institutions like pensions and endowments often negotiate hard on management fees, performance fees, and deal terms.—
Lee Ying Shan,
CNBC,
3 Oct. 2025
Cite this Entry
“Efficacy.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/efficacy. Accessed 8 Oct. 2025.
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