inefficacy

[ in-ef-i-kuh-see ]
/ ɪnˈɛf ɪ kə si /

noun

lack of power or capacity to produce the desired effect.

Origin of inefficacy

From the Late Latin word inefficācia, dating back to 1605–15. See in-3, efficacy
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

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