irrational

[ ih-rash-uh-nl ]
/ ɪˈræʃ ə nl /

adjective

noun

Mathematics. irrational number.

Origin of irrational

First recorded in 1425–75; late Middle English word from Latin word irratiōnālis. See ir-2, rational
Related forms
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for irrational

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 Formsirrationally, 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

Medicine 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.