UNREASONABLE Synonyms: 124 Similar and Opposite Words

unreasonable

adjective

ˌən-ˈrēz-nə-bəl

Definition of unreasonable

as in unwarranted

having no basis in reason or fact an unreasonable assumption

Synonyms & Similar Words

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Antonyms & Near Antonyms

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 However, critics like the American Civil Liberties Union have called the technology unreasonable surveillance. — Kendrick Calfee, Kansas City Star, 14 Oct. 2026 And the sense that Dodge had built something kind of unreasonable and then discovered that nobody tried to stop them. — New Atlas, 14 Oct. 2026 Brady pointed to a legal doctrine known as laches, which can prevent a party from pursuing a claim after an unreasonable delay that prejudices another party. — Gino Vicci, CBS News, 12 Oct. 2026 The factors most closely tied to burnout included unfair treatment, crushing workloads, unclear expectations, poor communication and support from managers, and unreasonable deadlines. — Christos Makridis, The Conversation, 7 Oct. 2026 See All Example Sentences for unreasonable

Recent Examples of Synonyms for unreasonable

Adjective

Kirk's attorneys cited Utah law guaranteeing crime victims the right to a speedy disposition of charges without unwarranted delay.

— Emma Bussey, FOXNews.com, 22 Oct. 2026
While we are relieved that Heidi has received medical care and is safe, we are outraged by this unwarranted attack on a journalist doing her job and urge a thorough investigation and follow-through from authorities.

— Arkansas Online, Arkansas Online, 17 Oct. 2026

Definition of unwarranted

Adjective

Giving any person a $100 million contract to coach a college athletic team is irrational.

— Letters to the Editor, The Orlando Sentinel, 28 Oct. 2026
The industrial revolutions of the past produced enormous value alongside bankruptcies, dislocations, and periods of irrational exuberance.

— Brian Solis, Forbes.com, 5 Oct. 2026

Definition of irrational

Adjective

The investigation was closed after authorities determined Thompson’s claims were unfounded, the department said.

— Elizabeth Campbell, Fort Worth Star-Telegram, 23 Oct. 2026
Stewart, a potent running quarterback for the Pittsburgh Steelers, was the talk of the industry when an unfounded rumor about him being gay threatened to derail everything.

— K. Thor Jensen, PC Magazine, 23 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 unleashed a series of personal and baseless attacks against Hamilton at the rally in Park City, Kansas -- about 10 miles north of Wichita -- with just two weeks out from election day as the balance of power in the Senate hangs in the balance.

— ABC News, ABC News, 20 Oct. 2026
The White House has consistently derided Bonta’s litigation against the administration as baseless and misguided.

— Kevin Rector, Los Angeles Times, 15 Oct. 2026

Definition of baseless

Adjective

Finally, the article argues that the federal lawsuit threatens state control over election administration and could fuel further claims that election results are illegitimate.

— Los Angeles Times, Los Angeles Times, 20 Oct. 2026
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

Definition of illegitimate

Adjective

Nvidia has gone to great lengths to secure support from game publishers, but many titles remain unsupported at the time of writing.

— Joe Osborne, PC Magazine, 17 Oct. 2026
This case involved a restaurant owner accused of underreporting more than US$2 million in business receipts and claiming unsupported depreciation deductions on rental properties.

— Kaitlin Newkirk, The Conversation, 14 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

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Style

“Unreasonable.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/unreasonable. Accessed 28 Oct. 2026.

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Synonyms of unreasonable

adjective

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