conclusive
Americanadjective
-
serving to settle or decide a question; decisive; convincing.
conclusive evidence.
- Synonyms:
- definitive
-
tending to terminate; closing.
adjective
-
putting an end to doubt; decisive; final
-
approaching or involving an end or conclusion
Other Word Forms
- conclusively adverb
- conclusiveness noun
- nonconclusive adjective
- nonconclusively adverb
- nonconclusiveness noun
Etymology
Origin of conclusive
1580–90; < Late Latin conclūsīvus, equivalent to Latin conclūs ( us ) (past participle of conclūdere to conclude; see conclusion) + -īvus -ive
Explanation
If you've got a theory that you're trying to prove, and you uncover a conclusive piece of evidence, then the case is closed. Conclusive means you've got your answer, you've proved your theory, and there can't be any doubt about it. If want to prove that frogs can speak, and you record a frog reciting "The Midnight Ride of Paul Revere," that would be conclusive evidence for your claim. But if the frog seemed to be mumbling and mainly making regular old frog noises, critics would say that your video was not conclusive. You can also use the word conclusive to describe winning something easily or by a large margin, like when the talent competition judges handed the tap-dancing bear a conclusive victory, and he moved on triumphantly to the finals.
Vocabulary lists containing conclusive
The Emancipation Proclamation (1862)
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Case Closed: Clud, Clus
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The Articles of Confederation (1777)
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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.
As in the less conclusive first season, it feels engineered to deliver the characters to happy, or relatively happy, endings, and to send viewers out not regretting their investment of time.
From Los Angeles Times • Apr. 16, 2026
The shot was more than 70% effective at preventing the disease in the trial, but not enough people contracted Lyme for the findings to be conclusive.
From The Wall Street Journal • Mar. 27, 2026
"It's not by itself conclusive, but it suggests that maybe the dynamo was in a slightly different regime than today," he said.
From Science Daily • Mar. 21, 2026
There is no conclusive evidence as to what those shipments contained.
From Barron's • Mar. 16, 2026
He describes the phases as providing ‘strong evidence that Venus moves in a sun-centred orbit’ when one might rather say that they provide conclusive evidence.
From "The Invention of Science" by David Wootton
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.
