effective

1 of 2

adjective

ef·​fec·​tive i-ˈfek-tiv How to pronounce effective (audio)
e-,
ē-,
ə-
1
a
: producing a decided, decisive, or desired effect
an effective policy
b
: impressive, striking
a gold lamé fabric studded with effective … precious stonesStanley 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
effectiveness noun
effectivity noun

effective

2 of 2

noun

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

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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.

Choose the Right Synonym for 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

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.
Recent Examples on the Web
Adjective
However, at Fulcrum, the policy is to administer treatments only every 12 weeks to prevent any potential antibody response against the toxin's peptide component, which could render the treatment less effective or ineffective. Nick Kasmik, USA TODAY, 18 May 2024 The camerawork is loose and supple, the moody textures of the many night scenes are effective and the use of vibrant color is invigorating. David Rooney, The Hollywood Reporter, 18 May 2024 See all Example Sentences for effective 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'effective.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

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

First Known Use

Adjective

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

Noun

1708, in the meaning defined above

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

Dictionary Entries Near effective

Cite this Entry

“Effective.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/effective. Accessed 24 May. 2024.

Kids Definition

effective

adjective
ef·​fec·​tive
i-ˈfek-tiv
1
a
: producing or able to produce a desired effect
effective treatment of a disease
b
: impressive, striking
an effective performance
2
: being in actual operation
the law becomes effective next year
effectively adverb
effectiveness noun

Medical Definition

effective

adjective
ef·​fec·​tive i-ˈfek-tiv How to pronounce effective (audio)
: producing a decided, decisive, claimed, or desired effect
a drug judged effective by an evaluating panel
effectively adverb
effectiveness noun

Legal Definition

effective

adjective
ef·​fec·​tive
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
effectiveness noun

More from Merriam-Webster on effective

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