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 effectivity (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 No vaccine is 100% effective in preventing the flu. Claire Gillespie, Health.com, "What Is the High-Dose Flu Vaccine, and Who Can Get It? Here's What Infectious Disease Experts Say," 24 Sep. 2020 The Food and Drug Administration only requires that a COVID-19 vaccine is proven to be 50% effective for those injected to be approved. Grady Mcgregor, Fortune, "Scientists say a gap in COVID vaccine research may keep us from returning to ‘normal’," 23 Sep. 2020 Redfield floated the possibility that a vaccine might be 70% effective at making those who take it immune. Brooke Baitinger, sun-sentinel.com, "Palm Beach County mask ordinance extended until at least Oct. 22," 21 Sep. 2020 During the pre-pandemic portion of the schedule, Middleton shot 49.9% overall and 41.8% from three-point range for a career-best 57.7% effective field-goal percentage. Matt Velazquez, Milwaukee Journal Sentinel, "Giannis unanimously selected as first-team all-NBA; Khris Middleton snubbed," 16 Sep. 2020 The flu vaccine, for example, is generally about 40% to 60% effective against the annual viral strain. Ricardo Alonso-zaldivar And Matthew Perrone, Star Tribune, "CDC head: Virus vaccine won't be widely available until summer of 2021," 16 Sep. 2020 According to the company’s research, the mask is up to 88% effective at filtering out airborne particles including viruses. Kathy Passero, cleveland, "6 face masks that are antimicrobial for added protection," 12 Sep. 2020 However, how effective the air purifier is depends on both the purifier itself and the pollution level of the air. Amanda Tarlton, USA TODAY, "Wildfire smoke and air purifiers: Here's what you need to know," 11 Sep. 2020 This builds on guidance the agency put out in June that said any Covid-19 vaccine should be at least 50% effective. Anna Edney, Bloomberg.com, "FDA Setting Higher Bar for Emergency Covid Vaccine Clearance," 10 Sep. 2020 Recent Examples on the Web: Noun In this scenario, infections will decline even if face masks are only 50-percent effective. John Timmer, Ars Technica, "Face masks don’t even have to work especially well to be effective," 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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Statistics for effective

Last Updated

30 Sep 2020

Cite this Entry

“Effective.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/effective. Accessed 1 Oct. 2020.

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More Definitions for effective

effective

adjective
How to pronounce effective (audio)

English Language Learners Definition of effective

: producing a result that is wanted : having an intended effect
of a law, rule, etc. : in use
: 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 effective medicines
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

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Comments on effective

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