In the planner's view, Rumsfeld had two goals: to demonstrate the efficacy of precision bombing and to "do the war on the cheap."—Seymour M. Hersh, New Yorker, 7 Apr. 2003Vaccines exist, but their efficacy against aerosolized plague is unknown.—Sharon Begley et al., Newsweek, 8 Oct. 2001… efficacy does not have to be demonstrated before homeopathic products are marketed.—Alison Abbott et al., Nature, 26 Sept. 1996
questioned the efficacy of the alarms in actually preventing auto theft
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Extract every efficacy endpoint, its p-value, confidence interval, and sample size.—Christiaan Hetzner, Fortune, 15 July 2025 For more than half a century, ACIP has met multiple times a year to deliberate on the efficacy of vaccine selection for millions of Americans.—Jesse Edwards, MSNBC Newsweek, 15 July 2025 From St John’s wort to vitamin D, the range of over-the-counter supplements for mental health support and wellbeing continues to expand at a rate faster than scientists can validate their efficacy.—New Atlas, 14 July 2025 The best wrinkle creams on Amazon prove that drugstore prices don’t diminish efficacy.—Kiana Murden, Vogue, 11 July 2025 See All Example Sentences for efficacy
Word History
Etymology
borrowed from Latin efficācia, from efficāc-, efficāx "capable of fulfilling a function, efficacious" + -ia-y entry 2
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