Word Origin
See more synonyms for efficacy on Thesaurus.com noun, plural ef·fi·ca·cies. capacity for producing a desired result or effect; effectiveness: a remedy of great efficacy. Show More
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. 2018
Related Words for efficacies adequacy ,
effectiveness ,
competence ,
virtue ,
potency ,
vigor ,
use ,
strength ,
force ,
ability ,
power ,
efficaciousness ,
energy ,
influence ,
effect ,
weight ,
capability ,
performance ,
success ,
sufficiency British Dictionary definitions for efficacies the quality of being successful in producing an intended result; effectiveness Show More
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
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Word Origin and History for efficacies n. 1520s, from Latin efficacia "efficacy, efficiency," from efficax (genitive efficacis ) "powerful, effective," from stem of efficere "work out, accomplish" (see effect ). Earlier in same sense was efficace (c.1200), from Old French eficace (14c.), from Latin efficacia ; also efficacite (early 15c.), from Latin efficacitatem .
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Online Etymology Dictionary, © 2010 Douglas Harper
