effective
Americanadjective
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adequate to accomplish a purpose; producing the intended or expected result.
effective teaching methods; effective steps toward peace.
-
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.
-
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.
Reverse-engineering existing technology yielded “the Toyota Corolla of drones”—cheap, easy to manufacture and devastatingly effective.
From The Wall Street Journal • Apr. 3, 2026
But according to Goldman Sachs, the combined effect of the ruling and the new levies is actually a reduction in the increase of the effective tariff rate since the beginning of 2025.
From Barron's • Apr. 2, 2026
Last month, her family took legal action against the Los Angeles Unified School District, alleging that school officials failed to investigate reports of bullying, adequately supervise student interactions or implement effective safety measures.
From Los Angeles Times • Apr. 2, 2026
Chief Pentagon spokesperson Sean Parnell said in a statement on social media that George "will be retiring from his position as the 41st Chief of Staff of the Army effective immediately".
From BBC • Apr. 2, 2026
Another especially effective strategy was disruption of the Indigenous trade networks, which caused food shortages and starvation.
From "An Indigenous People’s History of the United States" by Roxanne Dunbar-Ortiz
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.
