Try Our Apps


90s Slang You Should Know


[uhn-ree-zuh-nuh-buh l, -reez-nuh-] /ʌnˈri zə nə bəl, -ˈriz nə-/
not reasonable or rational; acting at variance with or contrary to reason; not guided by reason or sound judgment; irrational:
an unreasonable person.
not in accordance with practical realities, as attitude or behavior; inappropriate:
His Bohemianism was an unreasonable way of life for one so rich.
excessive, immoderate, or exorbitant; unconscionable:
an unreasonable price; unreasonable demands.
not having the faculty of reason.
Origin of unreasonable
First recorded in 1300-50, unreasonable is from the Middle English word unresonabel. See un-1, reasonable
Related forms
unreasonableness, noun
unreasonably, adverb
1, 2. senseless, foolish, silly. 2. preposterous, absurd, stupid, nonsensical. 3. extravagant. Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2017.
Cite This Source
Examples from the Web for unreasonable
Contemporary Examples
Historical Examples
  • Sim could not swim, and he began to flop about in the wildest and most unreasonable manner.

    Down The River Oliver Optic
  • "But, Bertha, you will not be so unreasonable," urged Madeleine.

    Fairy Fingers Anna Cora Mowatt Ritchie
  • But if you would at the same time not pay the one, and yet receive the other, you are unreasonable and foolish.

    The Enchiridion Epictetus
  • He was meddlesome, wrong-headed, unreasonable, and bold with it all.

    Stories Of Georgia Joel Chandler Harris
  • The public opinion of the various powers considers the conduct of the Japanese as unjustifiable and unreasonable.

    Japan Various
British Dictionary definitions for unreasonable


immoderate; excessive: unreasonable demands
refusing to listen to reason
lacking reason or judgment
Derived Forms
unreasonableness, noun
unreasonably, adverb
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
Word Origin and History for unreasonable

mid-14c., from un- (1) "not" + reasonable. Related: Unreasonably.

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source

Word of the Day

Difficulty index for unreasonable

Some English speakers likely know this word

Word Value for unreasonable

Scrabble Words With Friends

Nearby words for unreasonable