effective

adjective
ef·​fec·​tive | \i-ˈfek-tiv, 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 , 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

The reorganization will help our department better reflect the realities of how movies are released today, and build the connective tissue needed internally and externally to be effective and efficient. Pamela Mcclintock, The Hollywood Reporter, "Sony Pictures Issues Layoffs as Part of Marketing Reorganization," 11 July 2018 The central government issued red alerts for landslides in two mountain villages of northwestern Taiwan's Hsinchu county, effective Wednesday. Fox News, "Typhoon Maria barrels into China after pounding Taiwan," 11 July 2018 Chen allowed only an unearned run and three hits over six innings in one of his most effective and efficient outings in 13 starts this season. Craig Davis, Sun-Sentinel.com, "Barraclough blows save, but Marlins win in 10th on Rivera's hit," 3 July 2018 It has been shown to be more than 90 percent effective in HIV prevention when taken daily. Washington Post, "Out-Of-Pocket Costs Put HIV Prevention Drug Out Of Reach For Many At Risk," 11 July 2018 When the Small Wireless Facilities Deployment Act became effective in Illinois June 1, Lichterman said municipalities like Deerfield had 60 days to enact their own regulations or accept the ones contained in the state law. Steve Sadin, chicagotribune.com, "Deerfield moves to regulate small cell antennas," 9 July 2018 Pruitt delivered for Trump like few others in the Cabinet There’s been a robust back-and-forth about whether Pruitt was actually effective in implementing his agenda at the EPA. Umair Irfan, Vox, "Why Scott Pruitt lasted so long at the EPA, and what finally did him in," 7 July 2018 One study found this method to be effective in treating psoriasis. Ashley Welch, CBS News, "Woman lost her toenails after fish pedicure," 5 July 2018 But Zostavax was only about two-thirds effective in preventing shingles, and the protection was essentially gone just seven years after getting the vaccine. Julie Mazziotta, PEOPLE.com, "What to Know About the New Shingles Vaccine — and Why You Should Get It ASAP if You're Over 50," 5 July 2018

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

see effect entry 1

Noun

see effect entry 1

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Statistics for effective

Last Updated

4 Nov 2018

Look-up Popularity

Time Traveler for effective

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

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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

of a law, rule, etc. : in use

: starting at a particular time

effective

adjective
ef·​fec·​tive | \i-ˈfek-tiv \

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 \

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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