efficacious

adjective ef·fi·ca·cious \ ˌe-fə-ˈkā-shəs \

|Updated on: 3 Jun 2018

Tip: Synonym Guide

Examples: efficacious in a Sentence

: having the power to produce a desired effect

an efficacious remedy

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efficaciously

adverb

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efficaciousness

noun

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Examples of efficacious in a Sentence

taking a cookie break while studying is one of the most efficacious ways of rejuvenating the mind that I have ever discovered

Recent Examples of efficacious from the Web

Sephora: The cosmetics mecca is offering a sweet deal on their affordably priced but super efficacious in-house line, Sephora Collection.

— rachel jacoby zoldan, Glamour, "The Best Memorial Day 2018 Beauty Sales to Shop This Weekend," 23 May 2018
If strength and conditioning coaches, personal trainers, or physical therapists are armed with this type of information, then the most effective exercise selection and efficacious use of precious time with the athlete could be maximized.

— NOLA.com, "Optimum Performance: Targeting hip biomechanics to enhance Serena's performance," 6 Apr. 2018
The efficacious, enduring photographer has published a number of retrospective books that not only present a history of our time but offer a record for herself

— TIME.com, "Annie Leibovitz on Stephen Hawking," 26 Oct. 2017
And with the leeway Graham-Cassidy’s New Federalist framework would afford them, states might be able to find more efficacious ways to protect those people.

— theodore kupfer, National Review, "Jimmy Kimmel, Policy-Wonk Wannabe," 20 Sep. 2017
Kiehl's began as a neighborhood apothecary that always put its patrons first, so ensuring that Kiehl’s current fans have accessibility to our efficacious products in any neighborhood is important.

— sarah kinonen, Allure, "Kiehl's Is Coming to Sephora Stores," 28 July 2017
There remain many open questions in the field—how, why, and in what circumstances cognitive training is efficacious—and so painting in such broad strokes potentially undermines this important, ongoing research area.

— beth mole, Ars Technica, "Study: Lumosity boosts brain function as much as normal video games—by 0%," 10 July 2017
If the pilot program proves efficacious, it would be expanded within Colorado’s 18,000-inmate population and perhaps across the nation.

— the denver post editorial board, The Denver Post, "Tablet computers could prove valuable in helping reform inmates," 15 May 2017
This kind of brain-science has already proven efficacious: a preliminary study of humans working with help from machinated neuron tapping showed a six-fold increase in efficiency.

— noah shachtman, WIRED, "Darpa Wants Brainy Machines to Replace Bored G.I.s," 16 Apr. 2009

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'efficacious.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of efficacious

Latin efficac-, efficax, from efficere

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First Known Use: 1528

in the meaning defined above

See Words from the same year

efficacious Synonyms

Synonym Discussion of efficacious

effective, effectual, efficient, efficacious mean producing or capable of producing a result. effective stresses the actual production of or the power to produce an effect.

- an effective rebuttal

effectual suggests the accomplishment of a desired result especially as viewed after the fact.

- the measures to stop the pilfering proved effectual

efficient suggests an acting or a potential for action or use in such a way as to avoid loss or waste of energy in effecting, producing, or functioning.