English Dictionary

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efficacious (ˌɛfɪˈkeɪʃəs Pronunciation for efficacious



  1. capable of or successful in producing an intended result; effective as a means, remedy, etc

Derived Forms

ˌeffiˈcaciously adverb

Word Origin

C16: from Latin efficāx powerful, efficient, from efficere to achieve; see effect

Example Sentences Including 'efficacious'

"A quick and easy implant gives them a more humane, cost-effective choice that leaves their dogs intact but is equally efficacious.
Mail and Guardian (2004)
A few yards below the chapel is a healing well, particularly efficacious for afflictions of the eyes.
Begg, Ean & Rich, Deike On the Trail of Merlin - a guide to the Celtic mystery tradition
Right idea; An efficacious prescription for the Labour Party; Leading Article
Times, Sunday Times (2002)
The man seemed stronger, so perhaps JoJo's fever drench had been efficacious after all.
Murray, Stephen Death and Transfiguration
The results underline the value of context specific, pragmatic studies to evaluate the suitability of seemingly efficacious programmes.
British Medical Journal (2002)


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