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irrational

[ ih-rash-uh-nl ]
/ ɪˈræʃ ə nl /
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See synonyms for: irrational / irrationally on Thesaurus.com

adjective
noun
Mathematics. irrational number.
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Origin of irrational

First recorded in 1425–75; late Middle English word from Latin word irratiōnālis.See ir-2, rational

OTHER WORDS FROM irrational

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

How to use irrational in a sentence

British Dictionary definitions for irrational

irrational
/ (ɪˈræʃənəl) /

adjective
inconsistent with reason or logic; illogical; absurd
incapable of reasoning
maths
  1. not rational
  2. (as noun)an irrational
prosody (in Greek or Latin verse)
  1. of or relating to a metrical irregularity, usually the occurrence of a long syllable instead of a short one
  2. denoting a metrical foot where such an irregularity occurs

Derived forms of irrational

irrationally, adverbirrationalness, noun
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

Medical definitions for irrational

irrational
[ ĭ-răshə-nəl ]

adj.
Not rational; marked by a lack of accord with reason or sound judgment.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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