irrational

 
Pronunciation: /ɪˈraʃ(ə)n(ə)l/

adjective

  • 1not logical or reasonable: irrational feelings of hostility
  • not endowed with the power of reason.
  • 2 Mathematics (of a number, quantity, or expression) not expressible as a ratio of two integers, and having an infinite and non-recurring expansion when expressed as a decimal. Examples of irrational numbers are the number π and the square root of 2.

noun

Mathematics
  • an irrational number or quantity; a surd.

Derivatives

irrationality

Pronunciation: /-ˈnalɪti/
noun

irrationalize

(also irrationalise) verb

irrationally

adverb

Origin:

late Middle English: from Latin irrationalis, from in- 'not' + rationalis (see rational)