effective

adjective ef·fec·tive \ i-ˈfek-tiv , e- , ē- , ə- \

Definition of effective

1 a :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 :ready for service or action

effective manpower

3 :actual

the need to increase effective demand for goods

4 :being in effect :operative

the tax becomes effective next year

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 4

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effectiveness

noun

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effectivity

play \ˌe-ˌfek-ˈti-və-tē, i-, ē-, ə-\ noun

See effective defined for English-language learners

See effective defined for kids

Examples of effective in a Sentence

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.

Recent Examples of effective from the Web

Howard County Public School System Interim Superintendent Michael Martirano on Tuesday announced appointments to new administrative positions, effective Aug. 3.

— andrew michaels, Howard County Times, "Martirano announces second round of administrative appointments," 19 July 2017
If approved during separate shareholder votes, the deal is expected to become effective next week.

— emery p. dalesio, chicagotribune.com, "Shareholders weigh British American, Reynolds tobacco merger," 19 July 2017
Because of advances in fuel, materials and electronics, the new rockets, while smaller than some of the Space Age beasts, may be more efficient and cost-effective.

— miamiherald, "New generation of giant rockets is about to blast off," 17 July 2017
Large Stainless Steel #Lemon Squeezer Lemon Juicer Press for Orange Lime and Lemons Citrus 2.4’’ inner diameter, 0.88lbs Designed for effective extraction, this#hand-heldlemonsqueezer won't waste an ounce of juice.

— carly breit, Country Living, "You've Been Using a Lemon Juicer All Wrong," 14 July 2017
No one will mistake Priebus for, say, James Baker, Ronald Reagan’s supremely effective chief of staff.

— rich lowry, National Review, "Reince for President," 14 July 2017
Effective August 1, 2017, House Bill 483 could prove monumental, potentially pulling back the curtain on cancer clusters across the state.

— justin nobel, Longreads, "The Louisiana Environmental Apocalypse Road Trip," 13 July 2017
Indiana ranked 50th or worse in three out of five of the main categories (37th in the quality category and 33rd in effective transitions).

— darla carter, The Courier-Journal, "Kentucky and Indiana called the worst in US for long-term support of elderly, disabled," 11 July 2017
Look for a formula that contains l-ascorbic acid, one of the most effective forms of vitamin C. We like Paula's Choice Resist C15 Super Booster ($49; paulaschoice.com).

— lauren balsamo, Redbook, "How Long Does It Take Your Favorite Beauty Products to Work?," 10 July 2017

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.

Comparing efficient, effective, and proficient

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.

Origin and Etymology of effective

see ¹effect

NEW! Time Traveler

First Known Use: 14th century

See Words from the same year

effective Synonyms

Synonyms

effectual, efficacious, efficient, fruitful, operative, potent, productive

Synonym Discussion of effective

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

effective

noun ef·fec·tive \ i-ˈfek-tiv , e- , ē- , ə- \

Definition of effective

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

Origin and Etymology of effective

see ¹effect

NEW! Time Traveler

First Known Use: 1708

See Words from the same year

EFFECTIVE Defined for English Language Learners

effective

adjective

Definition of effective for English Language Learners

: producing a result that is wanted : having an intended effect
of a law, rule, etc. : in use
: starting at a particular time

EFFECTIVE Defined for Kids

effective

adjective ef·fec·tive \ i-ˈfek-tiv \

Definition of effective for Students

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.

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effectively

adverb

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effectiveness

noun

Word Root of effective

The Latin word facere, meaning “to make” or “to do,” and its form factus give us the roots fic, fact, and fect. Words from the Latin facere have something to do with making or doing something. To manufacture is to make goods. This is often done in a factory. Something difficult is hard to do. Anything effective does what it is meant to do.

Medical Dictionary

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

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effectively

adverb

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effectiveness

noun

Law Dictionary

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

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effectiveness

noun

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effective Synonyms

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EFFECTIVE Defined for English Language Learners

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