effective
Americanadjective
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adequate to accomplish a purpose; producing the intended or expected result.
effective teaching methods; effective steps toward peace.
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actually in operation or in force; functioning.
The law becomes effective at midnight.
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producing a deep or vivid impression; striking.
an effective photograph.
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prepared and available for service, especially military service.
noun
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a member of the armed forces fit for duty or active service.
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the effective total of a military force.
adjective
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productive of or capable of producing a result
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in effect; operative
effective from midnight
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producing a striking impression; impressive
an effective entrance
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(prenominal) actual rather than theoretical; real
the effective income after deductions
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(of a military force, etc) equipped and prepared for action
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physics (of an alternating quantity) having a value that is the square root of the mean of the squares of the magnitude measured at each instant over a defined period of time, usually one cycle See also root mean square
noun
Usage
What are other ways to say effective? The adjective effective describes things that are adequate to accomplish a purpose, or that produce the intended or expected result. But effective isn’t quite the same as effectual, efficacious, or efficient! Find out why on Thesaurus.com.
Related Words
operative. telling.
Other Word Forms
- effectively adverb
- effectiveness noun
- effectivity noun
- preeffective adjective
- quasi-effective adjective
- subeffective adjective
- supereffective adjective
- uneffective adjective
Etymology
Origin of effective
First recorded in 1350–1400; Middle English from Latin effectīvus “practical,” equivalent to effect(us), past participle of efficere ( effect ) + -īvus adjective suffix ( -ive )
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The company announced Monday that Maxson, the former finance chief at French energy company Schneider Electric, would take over as its finance lead effective immediately.
From Barron's • Apr. 7, 2026
Noisy circuits may appear trainable, but this is partly because noise has already reduced their effective complexity.
From Science Daily • Apr. 6, 2026
The ICE BofA US High Yield Index’s effective yield is 7.1%, versus 5.1% for the investment-grade bond index.
From The Wall Street Journal • Apr. 6, 2026
Stephanie Hunter McMahon, a tax-law professor at Indiana University’s Maurer School of Law, isn’t convinced that a tax strike is an effective form of protest.
From MarketWatch • Apr. 6, 2026
Cold is an effective alarm clock, and I was up before the sun.
From "The Marrow Thieves" by Cherie Dimaline
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
