in·​ef·​fi·​ca·​cy (ˌ)i-ˈne-fi-kə-sē How to pronounce inefficacy (audio)
: lack of power to produce a desired effect

Examples of inefficacy in a Sentence

Recent Examples on the Web When my depression hasn’t improved or worsened, providers have abruptly discharged me from their care without a treatment plan, or simply began treating me worse, as though the inefficacy of their therapies could only stem from my noncompliance or bad vibes. Maria Yagoda, Vogue, 25 Mar. 2024 The problem was the seeming inevitability of the juggernaut, the constancy of its forward motion, and the inefficacy of mere individuals in the face of such odds. Christopher Ketcham, Harper's Magazine, 1 Nov. 2023 Bosses who fail to express their appreciation also contribute to workers’ feelings of inefficacy. Michael P. Leiter, Scientific American, 1 Jan. 2015 Beyond its inefficacy, poorly delivered feedback may trigger defensive behaviors—too much negative feedback can create insecurities, dishonest feedback may misrepresent expectations and not enough feedback creates a distance between manager and employee. Eugene Dilan, Forbes, 13 Nov. 2023 There was hope Rodgers could change that long history of inefficacy when was acquired in an April trade in exchange for draft picks. Emmanuel Morgan, New York Times, 13 Sep. 2023 This set of emotions—exhaustion, feelings of inefficacy and cynicism—feed off one another, producing a vicious cycle of deepening burnout. Michael P. Leiter, Scientific American, 1 Jan. 2015 But their work is just the latest study to indicate that Republicans may have caused preventable deaths through their irresponsible messaging on the dangers of vaccines or the inefficacy of public health restrictions such as face masks and social distancing. Tori Otten, The New Republic, 25 July 2023 There are politicians in all camps who want to keep a lid on the conflict, generally not in service of any strategy for resolution but out of a sense of inefficacy and inertia. Michael Barnett, Foreign Affairs, 14 Apr. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'inefficacy.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Late Latin inefficacia, from Latin inefficac-, inefficax inefficacious, from in- + efficac-, efficax efficacious

First Known Use

circa 1615, in the meaning defined above

Time Traveler
The first known use of inefficacy was circa 1615

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Cite this Entry

“Inefficacy.” Dictionary, Merriam-Webster, Accessed 24 Apr. 2024.

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