irrational

adjective
UK: /ɪˈræʃənəl/
US: /ɪˈræʃənəl/

  1. Not based on clear thought or reason; unreasonable.

    1. It's irrational to be scared of something you don't understand.
    2. Her irrational fear of flying kept her from visiting her family abroad.

  2. Describes behavior or actions that don't follow logic or good judgment.

    1. His behavior became irrational after the bad news.
    2. The crowd's irrational reaction to the announcement caused chaos.

  3. (Mathematics) A number that cannot be expressed as a simple fraction.

    1. Pi is an irrational number that goes on forever.
    2. Students learn about irrational numbers in advanced math classes.

Synonyms

illogical unreasonable absurd foolish
irrational noun

  1. A number that cannot be expressed as a fraction of two integers.

    1. Square root of 2 is an irrational.
    2. Irrationals are often studied in number theory.

Frequently Asked Questions

The word "irrational" in English means: Not based on clear thought or reason; unreasonable., Describes behavior or actions that don't follow logic or good judgment., (Mathematics) A number that cannot be expressed as a simple fraction..

The phonetic transcription of "irrational" is /ɪˈræʃənəl/ in British English and /ɪˈræʃənəl/ in American English. Click the 🔊 button to hear both pronunciations.

Synonyms for "irrational": illogical, unreasonable, absurd, foolish.

Example usage of "irrational": "It's irrational to be scared of something you don't understand.". More examples on the page.