effective

adjective
ef·​fec·​tive | \ i-ˈfek-tiv How to pronounce effective (audio) , e-, ē-, ə- \

Definition of effective

 (Entry 1 of 2)

1a : producing a decided, decisive, or desired effect an effective policy
b : impressive, striking a gold lamé fabric studded with effective … precious stones— Stanley Marcus
2 : being in effect : operative the tax becomes effective next year
3 : actual the need to increase effective demand for goods
4 : ready for service or action effective manpower
5 of a rate of interest : equal to the rate of simple interest that yields the same amount when the interest is paid once at the end of the interest period as a quoted rate of interest does when calculated at compound interest over the same period — compare nominal sense 4

effective

noun

Definition of effective (Entry 2 of 2)

: one that is effective (see effective entry 1) especially : a soldier equipped for duty

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Other Words from effective

Adjective

effectiveness noun
effectivity \ ˌe-​ˌfek-​ˈti-​və-​tē How to pronounce effective (audio) , i-​ , ē-​ , ə-​ \ noun

Choose the Right Synonym for effective

Adjective

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

Comparing Efficient, Effective, and Proficient

Adjective

These three words cover some overlapping territory.

Efficient most often describes what is capable of producing desired results without wasting materials, time, or energy. While the word can be applied to both people and things, it is far more commonly applied to things, such as machines, systems, processes, and organizations. The focus of the word is on how little is wasted or lost while the desired results are produced.

Effective typically describes things—such as policies, treatments, arguments, and techniques—that do what they are intended to do. People can also be described as effective when they accomplish what they set out to accomplish, but the word is far more often applied to things.

Proficient typically describes people, and it often is followed by the preposition at. If you are proficient at something, you are very good at it. You are, in fact, so good at doing it that you are unusually efficient when you do it. One can also be proficient in something, such as a language.

Examples of effective in a Sentence

Adjective These commercials were extremely effective as marketing tools, but we now know that chocolate swimming pools and candy-coating showers play no part in the manufacture of real M&M's. Instead, the ellipsoid chocolate centers of plain M&M's are formed by machines. — David Owen, Atlantic, October 1988 My feeling is that by waiting for the right moment to let rip, a film is infinitely more effective, especially with characters you have come to like. — Clive Barker, in Cinefantastique, September 1987 But Tammy's most effective remedy for stress, both then and now, was the same as Imelda Marcos's: shopping up a storm. "It's kind of a hobby to help my nerves," she explained … — Jean Seligman, Newsweek, 8 June 1987 It's a simple but effective technique. He gave an effective speech.
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Recent Examples on the Web: Adjective APIs are one of the most effective tools healthcare providers have to share information with one another and can help healthcare providers meet this demand. Iddo Gino, Forbes, 16 Sep. 2021 Even as protection against infections eroded, the vaccine remained highly effective. Compiled Democrat-gazette Staff From Wire Reports, Arkansas Online, 16 Sep. 2021 Such was the case for Katalin Karikó, who, along with her colleague Drew Weissman, helped develop the messenger RNA (mRNA) technology that was used to produce the highly effective COVID vaccines made by Pfizer and Moderna. Tanya Lewis, Scientific American, 15 Sep. 2021 All three proved highly effective at preventing severe illness, hospitalizations and deaths from COVID-19. Leslie Gornstein, CBS News, 15 Sep. 2021 Smart Voting has been used twice in regional elections in the past two years, and has proven quite effective. Daria Litvinova, ajc, 14 Sep. 2021 Ivermectin has not been approved or proven effective as a treatment for COVID-19. Ella Lee, USA TODAY, 8 Sep. 2021 Chip design normally requires deep technical expertise and judgment, but machine learning has proven effective for automating elements of the process. Will Knight, Wired, 7 Sep. 2021 Years of experience have proven to McCartney that preparation could be one of the most effective tools once a storm hits. Gabriel Kinder, CNN, 2 Sep. 2021 Recent Examples on the Web: Noun California’s coronavirus dashboard showed an R-effective of 0.81 for San Francisco as of Wednesday. Kellie Hwang, San Francisco Chronicle, 9 June 2021 AstraZeneca is working with the Serum Institute, as is Novavax, whose vaccine looks to be ninety-six-per-cent effective. Sue Halpern, The New Yorker, 3 June 2021 One way is through applied topical insect repellent, the most (and arguably only) effective of which contain DEET. Larry Olmsted, Forbes, 28 Apr. 2021 But even for a team loaded at the position, the effective of Oregon’s ground game, especially in the second half, in its first two games is outlandish. oregonlive, 18 Nov. 2020 The agency had already announced that a vaccine would have to prove at least 50-percent effective at preventing COVID-19 to earn full approval. Beth Mole, Ars Technica, 24 Sep. 2020 In this scenario, infections will decline even if face masks are only 50-percent effective. John Timmer, Ars Technica, 12 June 2020

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

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First Known Use of effective

Adjective

14th century, in the meaning defined at sense 1a

Noun

1708, in the meaning defined above

History and Etymology for effective

Adjective

Middle English effectif, borrowed from Late Latin effectīvus "producing a result, efficient," going back to Latin, "involving an end product," from effectus, past participle of efficere "to make, bring about, produce, carry out" + -īvus -ive — more at effect entry 1

Noun

derivative of effective entry 1

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Time Traveler for effective

Time Traveler

The first known use of effective was in the 14th century

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Dictionary Entries Near effective

effectible

effective

effective aperture

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Statistics for effective

Last Updated

19 Sep 2021

Cite this Entry

“Effective.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/effective. Accessed 24 Sep. 2021.

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More Definitions for effective

effective

adjective

English Language Learners Definition of effective

: producing a result that is wanted : having an intended effect
: in use : active
: starting at a particular time

effective

adjective
ef·​fec·​tive | \ i-ˈfek-tiv How to pronounce effective (audio) \

Kids Definition of effective

1 : producing or able to produce a desired effect an effective vaccine
2 : impressive an effective speech
3 : being in operation The rule is effective immediately.

Other Words from effective

effectively adverb
effectiveness noun

effective

adjective
ef·​fec·​tive | \ i-ˈfek-tiv How to pronounce effective (audio) \

Medical Definition of effective

: producing a decided, decisive, claimed, or desired effect a drug judged effective by an evaluating panel

Other Words from effective

effectively adverb
effectiveness noun

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effective

adjective
ef·​fec·​tive

Legal Definition of effective

1 : producing a desired effect an effective revocation of the contract
2 : capable of bringing about an effect effective assistance of counsel — see also ineffective assistance of counsel
3 : being in effect
4 of a rate of interest : equal to the rate of simple interest that yields the same amount when the rate is paid once at the end of the interest period as a quoted rate of interest does when calculated at compound interest over the same period — compare nominal

Other Words from effective

effectiveness noun

More from Merriam-Webster on effective

Nglish: Translation of effective for Spanish Speakers

Britannica English: Translation of effective for Arabic Speakers

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