Definitions for Irrationalɪˈræʃ ə nl

This page provides all possible meanings and translations of the word Irrational

Random House Webster's College Dictionary

ir•ra•tion•alɪˈræʃ ə nl(adj.)

  1. lacking the faculty of reason; deprived of reason.

  2. lacking sound judgment or logic:

    irrational arguments.

  3. not controlled or governed by reason:

    irrational behavior.

  4. (of a number) not capable of being expressed exactly as a ratio of two integers. (of a function) not capable of being expressed exactly as a ratio of two polynomials. (of an equation) having an unknown under a radical sign or, alternately, with a fractional exponent.

    Category: Math

  5. of or pertaining to a syllable in Greek or Latin prosody whose quantity does not fit the meter.

    Category: Prosody

  6. Category: Math

    Ref: irrational number.

Origin of irrational:

1425–75; late ME < L


Princeton's WordNet

  1. irrational number, irrational(adj)

    a real number that cannot be expressed as a rational number

  2. irrational(adj)

    not consistent with or using reason

    "irrational fears"; "irrational animals"

  3. irrational(adj)

    real but not expressible as the quotient of two integers

    "irrational numbers"


  1. irrational(Noun)

    A real number that can not be expressed as the quotient of two integers, an irrational number.

  2. irrational(Adjective)

    Not rational; unfounded or nonsensical.

    an irrational decision

  3. irrational(Adjective)

    Of a real number, that cannot be written as the ratio of two integers.

    The number uE0009599uE001 is irrational.

  4. Origin: From irrationalis, from ir- + rationalis.

Webster Dictionary

  1. Irrational(adj)

    not rational; void of reason or understanding; as, brutes are irrational animals

  2. Irrational(adj)

    not according to reason; absurd; foolish

  3. Irrational(adj)

    not capable of being exactly expressed by an integral number, or by a vulgar fraction; surd; -- said especially of roots. See Surd


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