Standard Lemma guide

irrationality

noun · 5 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.

  • US: /ɪˌɹæʃ.əˈnæl.ə.ti/
  • US: /ɪˌɹæʃ.ɪˈnæl.ɪ.ti/
  • US: /əˌɹæʃ.əˈnæl.ə.ti/
  • US: Recorded audio is listed in the source snapshot.
  • rhymes with -ælɪti
  • CMU ARPABET: IH2 R AE2 SH AH0 N AE1 L AH0 T IY0 Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.

1

noun

Meaning 1

The quality or state of being irrational.

The state of being illogical or absurd.

Definition source: English Wiktionary via Wiktextract

Usage: countable, uncountable

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: absurdity, illogicality, fallaciousness

Antonyms: none provided

2

noun

Meaning 2

The quality or state of being irrational.

The property of being an irrational number.

Definition source: English Wiktionary via Wiktextract

Usage: countable, uncountable

Topics: mathematics, sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

3

noun

Meaning 3

The quality or state of being irrational.

The state of being incapable of reason or abstract thought.

Definition source: English Wiktionary via Wiktextract

Usage: countable, uncountable

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: unreason, mindlessness

Antonyms: none provided

4

noun

Meaning 4

Something that is irrational; the result of an illogical or absurd thought or action.

Definition source: English Wiktionary via Wiktextract

Usage: countable

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: absurdity

Antonyms: none provided

5

noun

Meaning 5

the state of being irrational; lacking powers of understanding

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: unreason

Antonyms: none provided

Broader terms: insanity

History

Etymology

From irrational + -ity. May also be analyzed as ir- + rationality.

Across languages

Translations

1 source translations are retained for this English entry.

  • Azerbaijani: irrasionallıq — state of being an irrational number