irrational

adjective · noun

Simple meaning

Not based on clear thinking or good reasons.

Pronunciation

Say it like this:

ihrashuhnuhl

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IPA pronunciation (US)

ɪˈɹæʃənəl

This word is pronounced essentially the same in American and British English, so one transcription covers both.

IPA (International Phonetic Alphabet) is a standard way of writing speech sounds.

Word Review

Definition

Everyday modern meanings first, grouped by part of speech.

adjective

Real but not expressible as the quotient of two integers
Not rational; unfounded, nonsensical or wrong-headed.
Not consistent with or using reason
mathematicsarithmeticnumber theorynot comparable
Of a real number, that cannot be written as the ratio of two integers.

noun

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

Word at a Glance

Difficulty: C1 · Advanced
Frequency: Uncommon
Typical Use: Varies by meaning

Word Aura™

How this word commonly comes across.

Aura for this meaning

This meaning: Real but not expressible as the quotient of two integers

Used this way, irrational is a reasonably familiar word that usually carries little praise or criticism of its own. It usually sounds natural in a wide range of settings.

Emotional tone: Neutral
Formality: Neutral
Intensity: Not strongly marked
How common: Moderately common
Connotation: No strong connotation
Usage feel: Neutral and straightforward

Word Aura describes common impressions, not a measurement. Tone changes with sentence, speaker, relationship and situation.

Common Patterns and Combinations

How this word naturally appears with others.

irrational numberirrational fearirrational behaviorirrational beliefirrational thinkingirrational element

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Word Family

Related forms, grouped by how they connect.

Compound terms

Established multiword terms.

irrational numbernounCompound term
A real number that cannot be expressed as a rational number.
irrational motivenounCompound term
A motivation that is inconsistent with reason or logic.
irrational hostilitynounCompound term
Extreme prejudice.
irrational impulsenounCompound term
A strong spontaneous and irrational motivation.

More about this wordSynonyms, forms, origin

Antonyms

Sense: real number that can not be expressed as the quotient of two integers

rational

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Dictionary data from Wiktionary via the Free Dictionary API. Simple meanings, combinations and word intelligence are built from verified reference data, no AI is used to load this page.