unsubstantiated

adjective

un·​sub·​stan·​ti·​at·​ed ˌən-səb-ˈstan(t)-shē-ˌā-təd How to pronounce unsubstantiated (audio)
Synonyms of unsubstantiatednext
: not proven to be true : not substantiated
an unsubstantiated rumor/report
a plausible but unsubstantiated theory

Synonyms of unsubstantiated

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Examples of unsubstantiated in a Sentence

an unsubstantiated claim that was thrown out of court
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
In spite of the rhetoric and unsubstantiated claims, highways don’t equal economic development. — Pete Harrison, Hartford Courant, 6 July 2026 The former president has also made unsubstantiated claims of vandalism causing the pool's problems. — Bill Goodykoontz, AZCentral.com, 26 June 2026 Conjecture over the evidence in Kirk’s killing has fueled unsubstantiated conspiracy theories that there might have been a second shooter, or that his death was staged. — Rebecca Boone, Chicago Tribune, 22 June 2026 Chang’s unsubstantiated speculation that Doremus might have been texting coworkers on her way to work was insufficient. — Dan Eaton, San Diego Union-Tribune, 18 May 2026 See All Example Sentences for unsubstantiated

Word History

First Known Use

circa 1775, in the meaning defined above

Time Traveler
The first known use of unsubstantiated was circa 1775

Rhymes for unsubstantiated

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Browse Nearby Words

unsubstantiate
unsubstantiated
unsubstituted
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Cite this Entry

“Unsubstantiated.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/unsubstantiated. Accessed 7 Jul. 2026.

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More from Merriam-Webster on unsubstantiated

Nglish: Translation of unsubstantiated for Spanish Speakers

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