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

Keep scrolling for more

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.
See More
Recent Examples on the Web: Adjective Davis, who had a 5.59 ERA in 9⅔ innings for Pittsburgh, has shown the potential for an effective fastball and breaking ball. BostonGlobe.com, 30 July 2021 The government said Friday that effective Monday, the measures would be extended to the full Tokyo metropolitan region as well as Osaka. Peter Landers, WSJ, 30 July 2021 This may turn out to be an effective campaign theme for Seif. New York Times, 30 July 2021 Van Damme’s real-life tribulations (including drug addiction, divorce and career valleys) to craft an unexpectedly effective drama. Michael Ordoña, Los Angeles Times, 30 July 2021 Short term, the team could look something like the 2019-20 Thunder, with Cunningham as a juggernaut version of Shai Gilgeous-Alexander and John Wall playing the role of a dramatically less effective Chris Paul. Robert Charles, Chron, 29 July 2021 Indeed, new research published this week adds to the evidence that keeping renters housed is an effective public health measure. Irina Ivanova, CBS News, 29 July 2021 The All-Star right-hander baffled the Giants with an effective mix of his four-seam fastball, sharp cutter and knuckle curve. Michael Wagaman, ajc, 29 July 2021 In terms of efficacy, the Pfizer and Moderna vaccines were found to be 95% and 94% effective, respectively. Chiara Vercellone, USA TODAY, 29 July 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.

See More

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

Keep scrolling for more

Learn More About effective

Time Traveler for effective

Time Traveler

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

See more words from the same century

Dictionary Entries Near effective

effectible

effective

effective aperture

See More Nearby Entries 

Statistics for effective

Last Updated

2 Aug 2021

Cite this Entry

“Effective.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/effective. Accessed 2 Aug. 2021.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

Keep scrolling for more

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 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

Keep scrolling for more

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

WORD OF THE DAY

Test Your Vocabulary

Difficult Spelling Words Quiz

  • alphabet pasta spelling help
  • Which is the correct spelling?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

TAKE THE QUIZ
Universal Daily Crossword

A daily challenge for crossword fanatics.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!