Dictionary.com

efficacy

[ ef-i-kuh-see ]
/ ˈɛf ɪ kə si /
Save This Word!
See synonyms for: efficacy / efficacies on Thesaurus.com

noun, plural ef·fi·ca·cies.

capacity for producing a desired result or effect; effectiveness: a remedy of great efficacy.

QUIZZES

QUIZ YOURSELF ON AFFECT VS. EFFECT!

In effect, this quiz will prove whether or not you have the skills to know the difference between “affect” and “effect.”
Question 1 of 7
The rainy weather could not ________ my elated spirits on my graduation day.
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
non·ef·fi·ca·cy, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021
  • That these two are different will easily be clear to anyone who passes in review their respective efficacies.

  • In 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 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Learning At Home Just Got Easier!