unreasonable

adjective

un·​rea·​son·​able
ˌən-ˈrēz-nə-bəl,
-ˈrē-zᵊn-ə-bəl How to pronounce unreasonable (audio)
Synonyms of unreasonablenext
1
a
: 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
unreasonableness
ˌən-ˈrēz-nə-bəl-nəs
-ˈrē-zᵊn-ə-bəl- How to pronounce unreasonable (audio)
noun
unreasonably
ˌən-ˈrēz-nə-blē
-ˈrē-zᵊn-ə-blē How to pronounce unreasonable (audio)
adverb

Synonyms

See All Synonyms & Antonyms in Thesaurus

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
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.
The words were harsh but the logic was not unreasonable. — George Caulkin, The Athletic, 24 Mar. 2025 This would not be an unreasonable proposition, considering the U.S. already pledged a security guarantee to Ukraine upon its return of all nuclear warheads to Russia by 1996, based on the Budapest Memorandum on Security Assurances. — Seung-Whan Choi, Chicago Tribune, 23 Mar. 2025 The Fourth Amendment protects against unreasonable search and seizures, but the line gets blurred within 100 miles of international borders. — Kathleen Wong, USA TODAY, 21 Mar. 2025 The production showcases the fractures that come to the surface when children are held to unreasonable standards and levels of excellence that no human being can uphold. — Aramide Tinubu, Variety, 18 Mar. 2025 See All Example Sentences for unreasonable

Word History

First Known Use

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

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

Browse Nearby Words

unreason
unreasonable
unreasoned
See all Nearby Words

Cite this Entry

“Unreasonable.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/unreasonable. Accessed 1 Apr. 2025.

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Legal Definition

unreasonable

adjective
un·​rea·​son·​able
: 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 violated— U.S. Constitution amend. IV
see also search, seizure
unreasonableness noun
unreasonably adverb

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