un·rea·son·able | \ˌən-ˈrēz-nə-bəl, -ˈrē-zᵊn-ə-bəl\

Definition of unreasonable 

1a : not governed by or acting according to reason unreasonable people

b : not conformable to reason : absurd unreasonable beliefs

2 : exceeding the bounds of reason or moderation working under unreasonable pressure

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Other Words from unreasonable

unreasonableness \ˌən-ˈrēz-nə-bəl-nəs, -ˈrē-zᵊn-ə-bəl- \ noun
unreasonably \ˌən-ˈrēz-nə-blē, -ˈrē-zᵊn-ə-blē \ adverb

Examples of unreasonable in a Sentence

I told him that I wouldn't pay unless he sent me a replacement. Am I being unreasonable? You are entitled to compensation for unreasonable delays.

Recent Examples on the Web

Each has painted the other side’s actions as unreasonable. Emily Stewart, Vox, "Can the US-China trade war be stopped? 11 experts weigh in.," 8 July 2018 Compelled to do what is right, Fiona visits Adam in the hospital to learn more about what, to her, seems like an unconventional and unreasonable decision. refinery29.com, "Emma Thompson Is A Judge Facing The Decision Of A Lifetime In Emotional New Movie," 14 June 2018 Some were a consequence of Holmes’s unreasonable demands. John Carreyrou, WIRED, "A New Look Inside Theranos’ Dysfunctional Corporate Culture," 21 May 2018 Regardless of how authentic the caller ID might look, the IRS warns that taxpayers should never fall for unreasonable demands. Susan Tompor, Detroit Free Press, "Robocalls are at a record high: How to avoid becoming a victim," 9 May 2018 Trump’s trade negotiators left Beijing Friday with no public sign of an agreement, reiterating that the U.S. shouldn’t make unreasonable demands. Tory Newmyer, Washington Post, "The Finance 202: Good news on the economy may not be a result of GOP tax cuts," 8 May 2018 An accommodation still must be reasonable, and if the noise level is excessive, that accommodation may ultimately be determined to be unreasonable. Kelly G. Richardson, sandiegouniontribune.com, "HOA Homefront: Are these rules valid?," 14 July 2018 So while Azar maintains the government plans to comply with last week’s reunification court order, he all but called it unreasonable to expect HHS to straighten out these cases in so little time. Dara Lind, Vox, "The Trump administration just admitted it doesn’t know how many kids are still separated from their parents," 5 July 2018 Mitchell argued the draw violated his constitutional rights to be free of unreasonable searches and seizures. Todd Richmond, The Seattle Times, "Wisconsin court OKs unconscious drunken drivers’ blood draws," 3 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'unreasonable.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of unreasonable

14th century, in the meaning defined at sense 1a

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Last Updated

9 Oct 2018

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The first known use of unreasonable was in the 14th century

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English Language Learners Definition of unreasonable

: not fair, sensible, or appropriate : not reasonable


un·rea·son·able | \ˌən-ˈrē-zᵊn-ə-bəl \

Kids Definition of unreasonable

: not fair, sensible, appropriate, or moderate an unreasonable schedule unreasonable behavior an unreasonable fear

Other Words from unreasonable

unreasonably \-blē \ adverb



Legal Definition of unreasonable 

: not reasonable : beyond what can be accepted: as

a : clearly inappropriate, excessive, or harmful in degree or kind an unreasonable delay an unreasonable restraint of trade

b : lacking justification in fact or circumstance an unreasonable inference especially : irrational sense b the agency decision was unreasonable

c : not supported by a warrant or by a valid exception to a warrant requirement (as when there is reasonable suspicion) and therefore unconstitutional the right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violatedU.S. Constitution amend. IV — see also search, seizure

Other Words from unreasonable

unreasonableness noun
unreasonably adverb

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