Word.ws English Dictionary

efficacy

/ˈɛf.ɪ.kə.si/

More pronunciations (1)Fewer pronunciations

Australia/ˈef.ɪ.kə.si/

efficacy noun: the ability to produce a desired effect under ideal testing conditions.

Noun

efficacy (usually uncountable, plural efficacies)

  1. (usually) The ability to produce a desired effect under ideal testing conditions.
    • […]and this hath even made me ſuſpect the efficacy of reliques, to examine the bones, queſtion the habits and appurtenances of Saints, and even of Chriſt himſelf.1642, Sir Thomas Browne, “Religio Medici [The Religion of a Doctor]”, in The Works Of the Learned Sr Thomas Brown, Kt., London: Tho. Basset et al., published 1686, page 15
    • No method of verification known to science is applicable to the efficacy of prayer. […] If, then, the efficacy of prayer eludes the test of science, and if even uncertainty may rest upon the connection between an event asked in prayer, and the prayer that sought it, is there any evidence by which...1875, Rev. Professor Wallace, “Prayer in Relation to Natural Law”, in Science and Revelation, Belfast: William Mullan, →ISBN, page 43
  2. (usually) A degree of ability to produce a desired effect; effectiveness.
    • Toothbrush with improved efficacy1996, Moskovich, Patent application PCT/US1996/003658

efficacy meaning in Hindi, Tamil, Bengali and Malayalam

efficacy in Hindi

प्रभावकारिता

efficacy in Tamil

உச்சவினை, பலாபலன், திறன்பாடு, செயற்செம்மை, செயல்வீரியம், செயற்செறிவு

efficacy in Bengali

কার্যকারিতা, কার্যকরীতা

efficacy in Malayalam

effectiveness, success, productiveness
ഫലദായകത്വം, വീര്യം, കഴിവ്, സാധകം, ഫലസിദ്ധി, സഫലത
More languagesFewer languages
efficacy in Sanskrit
वीर्य vīryà
efficacy in Indonesian
khasiat, kemanjuran, keampuhan, efikasi

Examples of efficacy in a sentence

  • The study examined the efficacy of geriatric interventions in reducing the frequency of falls among the elderly.
  • The algogenic organic matter affects the efficacy of water treatment.
  • The clean thrill of getting the right answer gave me a sense of efficacy and rootedness.

All 38 example sentences with efficacy

Synonyms of efficacy

Forms of efficacy

pluralefficacies

Plural of efficacy: efficacies

Origin of efficacy

From Old French efficace, from Late Latin efficācia (“efficacy”) (whence -acy), from efficāx (“efficacious”); see efficacious.

Words formed from efficacy

Questions about efficacy

What does efficacy mean?
Efficacy means the ability to produce a desired effect under ideal testing conditions.
What is efficacy in Hindi?
Efficacy in Hindi is प्रभावकारिता. See Efficacy meaning in Hindi.
What part of speech is efficacy?
Efficacy is a noun.
How do you pronounce efficacy?
Efficacy is pronounced /ˈɛf.ɪ.kə.si/ (UK).
What is the plural of efficacy?
The plural of efficacy is efficacies.

Words near efficacy in the dictionary

  1. efficacious
  2. efficaciously
  3. efficaciousness
  4. efficacities
  5. efficacity
  6. efficacy
  7. efficience
  8. efficiences
  9. efficiencies
  10. efficiency
  11. efficiency apartment

Source and license

Adapted from Wiktionary: efficacy (page history and authors); efficacy (Hindi, IndicTrans2 machine translation) (model and license); efficacy (Tamil Wiktionary) (page history and authors); efficacy (Bengali, IndicTrans2 machine translation) (model and license); efficacy (Olam, E.K. Kurup corpus) (dataset and license); वीर्य (Sanskrit) (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

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Cite this entry: “efficacy.” Word.ws, https://word.ws/efficacy. Based on Wiktionary, CC BY-SA 4.0.