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
Recent Examples on the Web
Examples are automatically compiled from online sources to
show current usage.Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
So, any vaccine safety and efficacy trial includes children who are getting the entire vaccine schedule in addition to the vaccine being tested, providing information on cumulative effects with every new addition.—ArsTechnica, 25 June 2025 In the morning, CDC staff presented data on COVID-19 vaccines, showing safety and efficacy as well as a reduction in hospitalizations and deaths.—Mary Kekatos, ABC News, 25 June 2025 Issues like homelessness, gas prices, public transit, the cost of living and the efficacy of state government are relentlessly portrayed as unique, catastrophic failings.—Deandre Evans, Mercury News, 25 June 2025 Operational Scale and Supply Chain Flexibility Operating 905 warehouses worldwide, including 624 in the U.S., Costco leverages its pricing advantage through extremely thin margins and the efficacy of its private-label brand, Kirkland Signature.—Trefis Team, Forbes.com, 24 June 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
Share