efficacious
[ ef-i-key-shuh s ]
/ ˌɛf ɪˈkeɪ ʃəs /
adjective
capable of having the desired result or effect; effective as a means, measure, remedy, etc.: The medicine is efficacious in stopping a cough.
Nearby words
effervescence, effervescent, effervescent salt, effete, effetely, efficacious, efficaciously, efficacity, efficacy, efficiency, efficiency apartment
Related forms
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for efficacious
British Dictionary definitions for efficacious
efficacious
/ (ˌɛfɪˈkeɪʃəs) /
adjective
capable of or successful in producing an intended result; effective as a means, remedy, etc
Derived Formsefficaciously, adverbefficaciousness, noun
Word Origin for efficacious
C16: from Latin efficāx powerful, efficient, from efficere to achieve; see effect
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 efficacious
efficacious
"sure to have the desired effect" (often of medicines), 1520s, from Latin efficaci-, stem of efficax (see efficacy) + -ous. Related: Efficaciously; efficaciousness.
Online Etymology Dictionary, © 2010 Douglas Harper