as in unreasonable
having no basis in reason or fact
an unsubstantiated claim that was thrown out of court
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Recent Examples of unsubstantiated
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
Trump on Monday blamed Rob Reiner’s outspoken opposition to the president for the actor-director’s killing, delivering the unsubstantiated claim in a social media post that seemed intent on decrying his opponents even in the face of a tragedy.
—Christopher Weber, Fortune, 15 Dec. 2025
The White House strategy makes the unsubstantiated claim that the populations of some European countries want an end to the war, but that their governments are subverting democratic processes and not delivering it.
—Haley Ott, CBS News, 5 Dec. 2025
William also might not be happy that Harry went on Colbert’s show, given that Colbert was forced to apologize after once cracking a joke about an unsubstantiated claim that William had been unfaithful.
—Martha Ross, Mercury News, 4 Dec. 2025
See All Example Sentences for unsubstantiated
Ilana Arougheti, Kansas City Star, 19 Dec. 2025
Trump on Monday blamed Rob Reiner’s outspoken opposition to the president for the actor-director’s killing, delivering the unsubstantiated claim in a social media post that seemed intent on decrying his opponents even in the face of a tragedy.
—Christopher Weber, Fortune, 15 Dec. 2025
The White House strategy makes the unsubstantiated claim that the populations of some European countries want an end to the war, but that their governments are subverting democratic processes and not delivering it.
—Haley Ott, CBS News, 5 Dec. 2025
William also might not be happy that Harry went on Colbert’s show, given that Colbert was forced to apologize after once cracking a joke about an unsubstantiated claim that William had been unfaithful.
—Martha Ross, Mercury News, 4 Dec. 2025
See All Example Sentences for unsubstantiated
Recent Examples of Synonyms for unsubstantiated
Adjective
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The issue is critical because the Fourth Amendment is supposed to protect people from invasive government actions in their homes, shielding them from unreasonable searches and seizures.—
Arkansas Online,
Arkansas Online,
24 Jan. 2026
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Love, in this cultural script, is supposed to feel good most of the time, and that expectation isn’t entirely unreasonable.—
Mark Travers,
Forbes.com,
24 Jan. 2026
Adjective
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Then $1,500 for Noma stateside isn’t entirely unfounded.—
Emily Wilson,
Bon Appetit Magazine,
26 Jan. 2026
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These fears are not unfounded, said Rhiannon Batchelder, a career coach based in Denver.—
Annie Nova,
CNBC,
24 Jan. 2026
Adjective
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This perspective that America’s founders supported insurrectionism is baseless.—
Douglas Letter,
Time,
6 Jan. 2026
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Kyiv has dismissed the allegation as a baseless lie aimed at building a pretext for the Kremlin to push ahead with its war.—
Yuliya Talmazan,
NBC news,
30 Dec. 2025
Adjective
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The list of unsupported transactions included a $348 hotel transaction in Lima, Peru; a nearly $1,700 meal at a Dubai steakhouse; and about $1,500 in plane tickets through Fiji Airways, all of which corresponded to the dates of the social media posts.—
Ishani Desai,
Sacbee.com,
30 Jan. 2026
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Mirabal said the response from employees left her stunned and feeling unsupported.—
Abby Dodge,
CBS News,
29 Jan. 2026
Cite this Entry
“Unsubstantiated.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/unsubstantiated. Accessed 31 Jan. 2026.
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