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
-
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.
Synonym Usage
operative. telling.
Other Word Forms
Derived Forms
Etymology
Origin of effective
First recorded in 1350–1400; Middle English from Latin effectīvus “practical,” equivalent to effect(us), past participle of efficere ( see effect) + -īvus adjective suffix ( see -ive)
Explanation
If your email outlining a plan to reduce office paper waste resulted in a 20 percent reduction in paper use, that means your plan was effective: it did what you wanted it to do. The adjective effective has many shades of meaning, but you'll usually see it describing something that's able to produce a desired goal. Effective traces back to the Latin word effectivus, from efficere, meaning “work out, accomplish,” and that meaning still holds true. Something effective gets the job done. As President, hopefully your policies are effective. We also use effective for something real and in effect, like the effective price of gas, or your effective grounding.
Vocabulary lists containing effective
"Diary of a Wimpy Kid" by Jeff Kinney
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Hatchet
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STAAR English I: The Language of the Test 1
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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.
When Congress passed the Anti-Terrorism and Effective Death Penalty Act in 1996, it imposed strict filing deadlines, strengthened rules against multiple petitions, and expanded deference to state court decisions.
From Slate • May 29, 2026
Effective immediately, if a family is considering visiting Mt.
From The Wall Street Journal • Mar. 6, 2026
"Effective immediately we are deploying body cameras to every officer in the field in Minneapolis," DHS Secretary Kristi Noem wrote on X on Monday.
From BBC • Feb. 2, 2026
Effective macroeconomic management aims to keep that machine running neither too hot nor too cold.
From MarketWatch • Jan. 5, 2026
Effective and inexpensive methods of local control have been known for years.
From "Silent Spring" by Rachel Carson
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.
