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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Examples of efficacy in a Sentence
Recent Examples on the Web
Policymakers amp up the anti-vaccine rhetoric, influencing public opinion about their safety and efficacy.
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Lisa Jarvis, The Mercury News, 16 Oct. 2024
Traditional antiviral drugs, while valuable, are largely specific to single viruses, and thus risk losing efficacy when new strains occur.
—Jano Costard, Fortune Europe, 16 Oct. 2024
That trial also showed the vaccine was safe and led to NextGen funding for a larger trial of the vaccine’s efficacy.
—Stephani Sutherland, Scientific American, 15 Oct. 2024
During evaluations, each tester reviewed ingredient lists and took notes on ease of use, scent, and overall efficacy.
—Brigitt Earley, Glamour, 3 Oct. 2024
See all Example Sentences for efficacy 
Lisa Jarvis, The Mercury News, 16 Oct. 2024
Traditional antiviral drugs, while valuable, are largely specific to single viruses, and thus risk losing efficacy when new strains occur.
—Jano Costard, Fortune Europe, 16 Oct. 2024
That trial also showed the vaccine was safe and led to NextGen funding for a larger trial of the vaccine’s efficacy.
—Stephani Sutherland, Scientific American, 15 Oct. 2024
During evaluations, each tester reviewed ingredient lists and took notes on ease of use, scent, and overall efficacy.
—Brigitt Earley, Glamour, 3 Oct. 2024
See all Example Sentences for efficacy
These examples are programmatically compiled from various online sources to illustrate current usage of the word 'efficacy.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
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“Efficacy.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/efficacy. Accessed 31 Oct. 2024.
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