1,400 new words in our dictionary! — Parasocial, glow-up, promposal & more
1,400 new words in our dictionary! — More

efficacity

noun

ˌe-fə-ˈka-sə-tē How to pronounce efficacity (audio)
Definition of efficacitynext
as in efficacy
the power to produce a desired result the limited efficacity of the primitive tool as an instrument for cutting raw meat

Synonyms & Similar Words

Relevance

Antonyms & Near Antonyms

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Recent Examples of efficacity Employing touchscreens for voting results in the adoption of technology for its own sake rather than to provide efficacity. — Letter Writers, Twin Cities, 10 Nov. 2019
Recent Examples of Synonyms for efficacity
  1. efficacy
  2. effectiveness
Noun
  • The Pentagon has rolled out formal guidance for mandatory testosterone testing for male service members 30 and older, a policy that leaves out women for now and faces questions from medical experts about the need and efficacy of such a program.
    — ABC News, ABC News, 18 Sep. 2026
  • This construct measures four developable capacities—hope, efficacy, resilience and optimism, collectively known as HERO.
    — Expert Panel®, Forbes.com, 18 Sep. 2026
Definition of efficacy
Noun
  • In testing the holiday period’s effectiveness, the report also verifies that spending at peak periods of demand does not guarantee the highest marginal return on media spend (MROM).
    — Arthur Zaczkiewicz, Footwear News, 24 Sep. 2026
  • This inevitably creates inequities across student access, workforce preparation, cybersecurity and institutional effectiveness.
    — Tarini Mehta, Sacbee.com, 24 Sep. 2026
Definition of effectiveness

Browse Nearby Words

efficaciousness
efficacity
efficacy
See all Nearby Words

Cite this Entry

“Efficacity.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/efficacity. Accessed 25 Sep. 2026.

Copy Citation
Last Updated: - Updated example sentences
Love words? Need even more definitions?

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

More from Merriam-Webster

Word of the Day

Listen to the pronunciation of tactile

See Definitions and Examples »

Popular in Grammar & Usage

See More

Do You Need a New Language Peeve?

More Commonly Mispronounced Words

Why do we use apostrophes to show possession?

Merriam-Webster’s Great Big List of Words You Love to Hate

'A' or 'an'? What about before 'h'? An Indefinite Article Guide
See More

Popular in Wordplay

See More

The Longest Long Words List

9 Words That Sound Like Insults But Aren't

Back to School Vocabulary

14 Phobias You Probably Haven't Heard Of

The Words of the Week - Sept. 25
See More

Popular

See More

Do You Need a New Language Peeve?

The Longest Long Words List

9 Words That Sound Like Insults But Aren't
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
image of the words cracker fly and sale arranged in a triangle with the word fire in the middle
Triple Play Quiz Find the word that pairs with each of the three g...
See All