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

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.
Multiple women came forward with detailed and serious allegations—including specific claims of drugging, rape, and assault—relatively quickly after initial reports, suggesting a verifiable pattern rather than mere unsubstantiated rumor. Los Angeles Times, 17 Apr. 2026 The push for peptides (both in injectable and non-injectable forms) has accelerated in recent years as influencers and manufacturers alike tout myriad benefits, many unsubstantiated by research. Mary Walrath-Holdridge, USA Today, 1 Apr. 2026 March 26, 2026 The MyPillow founder and right-wing politico has been sued numerous times for pushing unsubstantiated claims about alleged fraud in the 2020 presidential election. Brian Niemietz, New York Daily News, 27 Mar. 2026 Kern recently founded the Hoosier Enquirer, an independent news website that has leveled unsubstantiated allegations of election fraud against Sweeney Bell. Jordan Smith, IndyStar, 26 Mar. 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

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Cite this Entry

“Unsubstantiated.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/unsubstantiated. Accessed 28 Apr. 2026.

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