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.
The Kremlin looked to be doubling down on efforts to prolong the Ukraine war, making unsubstantiated claims that Kyiv had sought to attack one of Russian President Vladimir Putin’s residences, while Moscow’s forces launched a large-scale drone attack in southern Ukraine. Prashant Rao, semafor.com, 31 Dec. 2025 In 2024, the former Mesa County election clerk was sentenced for tampering with voting equipment to prove unsubstantiated voter fraud claims in 2020. David Zimmermann, The Washington Examiner, 31 Dec. 2025 Members of a key vaccine advisory committee suggested digging into concerns, and Kennedy has made unsubstantiated claims that the additive is linked to allergies and autism. Kayla Hayempour, NBC news, 26 Dec. 2025 Sherman was the subject of an investigation spearheaded by then-Johnson County Sheriff Calvin Hayden over unsubstantiated allegations of voter intimidation in 2022. Ilana Arougheti, Kansas City Star, 19 Dec. 2025 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 8 Jan. 2026.

More from Merriam-Webster on unsubstantiated

Last Updated: - Updated example sentences
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