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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Real-time, auditable settlement reduces operational and counterparty risk and can even enhance sanctions efficacy by making flows more traceable.—Chris Maurice, Fortune, 3 Oct. 2025 The findings on the effect of treatment duration and age on berberine efficacy are conflicting.—Trang Tran, Verywell Health, 30 Sep. 2025 This would forego the need for a larger phase 3 study, though other trials may be done to confirm the treatment’s efficacy.—Allison Parshall, Scientific American, 30 Sep. 2025 Named after the island’s Indigenous name, Rapa Nui, the drug rapamycin was initially developed as an immunosuppressant to prevent organ transplant rejection and to improve the efficacy of stents to treat coronary artery disease.—Ted Powers, The Conversation, 29 Sep. 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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