efficacious

adjective
ef·​fi·​ca·​cious | \ ˌe-fə-ˈkā-shəs How to pronounce efficacious (audio) \

Definition of efficacious

: having the power to produce a desired effect an efficacious remedy

Keep scrolling for more

Other Words from efficacious

efficaciously adverb
efficaciousness noun

Choose the Right Synonym for 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. an efficient small car efficacious suggests possession of a special quality or virtue that gives effective power. a detergent that is efficacious in removing grease

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 on the Web Certainly the myth of the cowboy is an efficacious myth, one based first of all upon a deep response to nature. Larry Mcmurtry, Harper's magazine, "American Cowboys," 28 Oct. 2019 The associated novel regimen will hopefully provide a shorter, more easily manageable and highly efficacious treatment for those in need. Beth Mole, Ars Technica, "How a new antibiotic destroys extremely drug-resistant tuberculosis," 16 Aug. 2019 In the past 20 years, this technology has proved efficacious. Costas Synolakis, WSJ, "The Art of Predicting Unpredictable Tsunamis," 3 Oct. 2018 Skinfix has quite literally built its name on offering efficacious products that address a variety of skin concerns, including dryness and eczema. Karina Hoshikawa, Allure, "Exclusive: Skinfix's Products Are Getting More Eco-Friendly Packaging — and Coming to Sephora," 19 Mar. 2019 The brand's Vitamin C Serum and D-Bronzi Serum are everything, and people swear by the line's efficacious yet gentle formulas. Bella Cacciatore, Glamour, "Drunk Elephant's Vegan Retinol Doesn't Irritate My Sensitive Skin," 26 Dec. 2018 Fast forward to today, where advancements have made the aluminum salts in antiperspirants efficacious but mild, says Melissa Torres, manager for North America deodorants and antiperspirants at Degree. Cassie Shortsleeve, Popular Mechanics, "How 5 Everyday Products Have Changed Through the Ages," 10 Dec. 2018 Sometimes expletives are just entertaining and efficacious, and this is particularly true for people in positions of power—which, by its very nature, has a way of conferring the Bad Mouthkeeping Seal of Approval on anything a person chooses to say. Gully Wells, Town & Country, "Elegant Expletives: A Socialite's Guide to the F-Bomb," 7 Aug. 2014 What makes this product so efficacious is its combination of hydrating ingredients, which are extra strong because they're designed for the feet. Rachel Jacoby Zoldan, SELF, "This Foot Cream Is Actually the Best Hand Cream of All Time," 12 Oct. 2018

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.

See More

First Known Use of efficacious

1528, in the meaning defined above

History and Etymology for efficacious

borrowed from Middle French efficace "effective" or its source Latin efficāc-, efficāx "capable of fulfilling a function, effective" (from efficere "to make, bring about, produce, carry out" + -āc-, -āx, deverbal suffix denoting habitual or successful performance) + -ious — more at effect entry 1, audacious

Keep scrolling for more

Learn More about efficacious

Time Traveler for efficacious

Time Traveler

The first known use of efficacious was in 1528

See more words from the same year

Listen to Our Podcast about efficacious

Statistics for efficacious

Cite this Entry

“Efficacious.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/efficacious. Accessed 25 Feb. 2020.

Keep scrolling for more

More Definitions for efficacious

efficacious

adjective
How to pronounce efficacious (audio)

English Language Learners Definition of efficacious

formal : having the power to produce a desired result or effect

Keep scrolling for more

More from Merriam-Webster on efficacious

Thesaurus: All synonyms and antonyms for efficacious

Rhyming Dictionary: Words that rhyme with efficacious

Spanish Central: Translation of efficacious

Nglish: Translation of efficacious for Spanish Speakers

Comments on efficacious

What made you want to look up efficacious? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

See Definitions and Examples »

Get Word of the Day daily email!

Test Your Vocabulary

More Confusing Words—Quiz

  • cats on impossible timber
  • The magician ______ moved the selected card to the top of the deck.
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Bee Cubed

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!