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.
QUIZ
TAKE JOY IN ACING THIS QUIZ ON “PRIDE” SYNONYMS
Hold your head up high as you embark on this quiz that explores some of the synonyms and meanings of “pride.”
Question 1 of 7
What does "dignity" mean?
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, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use efficacy in a sentence

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
FEEDBACK