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Added 9 October 2026

irrational

/ɪˈɹæʃ.(ə.)nəl/ adjective

Latin root: irratiōnālis Wiktionary

adjective Definition from Wiktionary (CC BY-SA). Pronunciation from Wiktionary, via Kaikki.org. More about irrational at Wordnik → Where our words come from →

Not rational; unfounded, nonsensical or wrong-headed.
an irrational decision
Of a real number, that cannot be written as the ratio of two integers.
The number π is irrational.

noun

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

Origin

From Latin irratiōnālis, from ir- + ratiōnālis.

From Wiktionary, via Kaikki.org (CC BY-SA)

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