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

Relevance

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
  • The pullback isn't totally unfounded given the problems in its medical devices business.
    — Kevin Stankiewicz, CNBC, 13 Oct. 2026
  • Its inclusion in the documentary has provided ammunition for Musk supporters and his lawyers to discredit the film, pointing to an unfounded conspiracy theory about SpaceX’s Starlink satellites interfering in the election.
    — ABC News, ABC News, 12 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
  • Trump’s obsession with baseless election fraud claims and threats to rig or militarize our elections won’t help the recent college grad who’s sent out 300 resumes but can’t get a job.
    — S.E. Cupp, New York Daily News, 8 Oct. 2026
  • 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
Definition of baseless
Adjective
  • An adult child can claim authority over the meaning of a life without proving that everything inherited is therefore illegitimate.
    — Literary Hub, Literary Hub, 9 Oct. 2026
  • Saman admitted to purchasing much of his inventory from brokers or middlemen, which the department identified as illegitimate distributors of the brands.
    — Glenn Taylor, Footwear News, 8 Oct. 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

Browse Nearby Words

unreason
unreasonable
unreasonableness
See all Nearby Words

Cite this Entry

“Unreasonable.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/unreasonable. Accessed 16 Oct. 2026.

Copy Citation
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Last Updated: - Updated example sentences

More from Merriam-Webster

Word of the Day

Listen to the pronunciation of zenith

See Definitions and Examples »

Popular in Grammar & Usage

See More

'Affect' vs. 'Effect'

Merriam-Webster’s Great Big List of Words You Love to Hate

The Exceptions of '-s' and '-es' Plurals

Is it 'nerve-racking' or 'nerve-wracking'?

What's the difference between 'fascism' and 'socialism'?
See More

Popular in Wordplay

See More

16 Food Words Recently Added to the Dictionary

The Real Origin of 'Supercalifragilistic'

9 Words That Sound Like Insults But Aren't

7 Words for Bad Endings and Rough Situations

The Words of the Week - Oct. 16
See More

Popular

See More

'Affect' vs. 'Effect'

16 Food Words Recently Added to the Dictionary

The Real Origin of 'Supercalifragilistic'
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
a cup of tea and a golf ball on tee side by side
Quiz: Sounds Like... Choose the word that sounds like it fits the clue...
See All