efficacy

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noun ef·fi·ca·cy \ˈe-fi-kə-sē\

Definition of efficacy

plural

efficacies

  1. :  the power to produce an effect

Examples of efficacy in a sentence

  1. 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. 2003

  2. Vaccines exist, but their efficacy against aerosolized plague is unknown. —Sharon Begley et al., Newsweek, 8 Oct. 2001

  3. efficacy does not have to be demonstrated before homeopathic products are marketed. —Alison Abbott et al., Nature, 26 Sept. 1996

  4. questioned the efficacy of the alarms in actually preventing auto theft

Recent Examples of efficacy from the web

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Origin and Etymology of efficacy

see efficacious


First Known Use: 13th century


EFFICACY Defined for English Language Learners

efficacy

play
noun ef·fi·ca·cy \ˈe-fi-kə-sē\

Definition of efficacy for English Language Learners

  • : the power to produce a desired result or effect



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