unreasonable

adjective

ˌən-ˈrēz-nə-bəl
Definition of unreasonablenext
1
as in unwarranted
having no basis in reason or fact an unreasonable assumption

Synonyms & Similar Words

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Antonyms & Near Antonyms
2
as in irrational
not using or following good reasoning an unreasonable respect for a man who did not deserve it

Synonyms & Similar Words

Antonyms & Near Antonyms

Example Sentences

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.
Recent Examples of unreasonable At the outset of the Biden administration in January 2021, NASA was still targeting a 2024 lunar landing, even though this was widely seen as unreasonable. — Eric Berger, ArsTechnica, 23 Sep. 2026 But Universal Ostrich Farms, a beak-to-tail-feathers operation that has sold everything from the animals’ meat to salves rendered from their fat, chose to challenge the order as unfair and unreasonable. — J. B. MacKinnon, Harpers Magazine, 22 Sep. 2026 Vagmaxxing seems the logical offshoot of a trend that prizes unreasonable, unrealistic body modification to the point of impossible AI perfection and transhumanism—scary enough! — Valerie Monroe, Allure, 21 Sep. 2026 Accurate voter lists and lawful mail-voting options are not unreasonable demands. — Lee Moak, New York Daily News, 18 Sep. 2026 See All Example Sentences for unreasonable
Recent Examples of Synonyms for unreasonable
  1. unwarranted
  2. irrational
  3. unfounded
  4. unreasoning
  5. baseless
  6. illegitimate
  7. unsupported
  8. groundless
Adjective
  • Critics have argued that much of the data collected is from people who are not suspected of any wrongdoing, amounting to unwarranted surveillance of lawful activities.
    — Carlos E. Castañeda, CBS News, 29 Sep. 2026
  • Given the fact Iger did return to the company, that belief was not unwarranted.
    — Bethy Squires, Vulture, 24 Sep. 2026
Definition of unwarranted
Adjective
  • The industrial revolutions of the past produced enormous value alongside bankruptcies, dislocations, and periods of irrational exuberance.
    — Brian Solis, Forbes.com, 5 Oct. 2026
  • If anyone can reconstruct Apéry’s reasoning, the odd values of zeta may finally be proven irrational.
    — Lyndie Chiou, Scientific American, 2 Oct. 2026
Definition of irrational
Adjective
  • In the lead-up to the 2022 vote, Jair Bolsonaro repeatedly cast unfounded doubts on Brazil's electronic voting system.
    — Arkansas Online, Arkansas Online, 4 Oct. 2026
  • Alito’s concerns are not unfounded, as threats to members in recent history have raised alarm about justices’ safety.
    — Claire Carter, The Washington Examiner, 4 Oct. 2026
Definition of unfounded
Adjective
  • But in each event—in the living act, the undoubted deed—there, some unknown but still reasoning thing puts forth the mouldings of its features from behind the unreasoning mask.
    — Literary Hub, Literary Hub, 6 July 2026
  • Roosevelt surely understood that nameless, unreasoning, unjustified fear cannot be eradicated.
    — New York Times, New York Times, 9 June 2026
Definition of unreasoning
Adjective
  • Homeland Security Secretary Markwayne Mullin publicly claimed in July — without providing evidence — that there may be more than 190,000 such voters on California rolls, a claim California officials dismissed as baseless.
    — Kevin Rector, Los Angeles Times, 29 Sep. 2026
  • Supporters of the three men said the allegations were baseless and contradicted by documentary evidence.
    — ABC News, ABC News, 23 Sep. 2026
Definition of baseless
Adjective
  • None of that is illegitimate, and none of it shows up on a data-residency dashboard.
    — Dr. Aditya Vikram Kashyap, Forbes.com, 22 Sep. 2026
  • The researchers suspect that others were created by AI that either hallucinated or, just like the AI agents browsing their file, couldn’t distinguish between legitimate and illegitimate instructions.
    — Dan Goodin, ArsTechnica, 27 Aug. 2026
Definition of illegitimate
Adjective
  • The defense said the government’s theory is unsupported and urged the judge to dismiss the charges.
    — Kaelan Deese, The Washington Examiner, 7 Oct. 2026
  • Short text, editing, translation and unsupported models can all produce undetected content.
    — Aamir Khollam, Interesting Engineering, 5 Oct. 2026
Definition of unsupported
Adjective
  • Ye Khaung Kyaw and the two other men charged in connection with the case have said the accusations against them are groundless.
    — Arkansas Online, Arkansas Online, 24 Sep. 2026
  • Social media in South Korea have been filled with messages stoking fears about safety on Jeju, with some spreading groundless rumors and deriding the island.
    — Hyung-Jin Kim, Los Angeles Times, 27 Aug. 2026
Definition of groundless

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unreason
unreasonable
unreasonableness
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Cite this Entry

“Unreasonable.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/unreasonable. Accessed 13 Oct. 2026.

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