efficacy

[ ef-i-kuh-see ]
/ ˈɛf ɪ kə si /

noun, plural ef·fi·ca·cies.

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

Origin of efficacy

1520–30; < Latin efficācia, equivalent to efficāc- (see efficacious) + -ia -y3

Related forms

non·ef·fi·ca·cy, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for efficacy

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