efficacy
[ ef-i-kuh-see ]
/ ˈɛf ɪ kə si /
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noun, plural ef·fi·ca·cies.
capacity for producing a desired result or effect; effectiveness: a remedy of great efficacy.
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Which of the following nouns has an irregular plural form?
Sometimes ef·fi·cac·i·ty [ef-i-kas-i-tee] /ˌɛf ɪˈkæs ɪ ti/ .
Origin of efficacy
First recorded in 1520–30; from Latin efficācia, equivalent to efficāc- “effective, effectual” + -ia noun suffix; see efficacious, -y3
OTHER WORDS FROM efficacy
non·ef·fi·ca·cy, nounDictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022
How to use efficacy in a sentence
That these two are different will easily be clear to anyone who passes in review their respective efficacies.
The Consolation of Philosophy|BoethiusIn silence and secrecy thought has been working, and the benignant efficacies of concealment speak for themselves.
Ku Klux Klan|J. C. Lester
British Dictionary definitions for efficacy
efficacy
/ (ˈɛfɪkəsɪ) /
noun
the quality of being successful in producing an intended result; effectiveness
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
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