irrational
/ɪˈɹæʃ.(ə.)nəl/adjective, noun
irrational is spelled I-R-R-A-T-I-O-N-A-L: 10 letters and 4 syllables. It appears 3.6 times per million words in written English, the 13,695th most frequent word form (wordfreq, 2021 data). As an adjective, irrational means “Not rational; unfounded, nonsensical or wrong-headed” (English Wiktionary, September 2026).
How many letters and syllables are in irrational?
| Letters | 10: I-R-R-A-T-I-O-N-A-L |
|---|---|
| Syllables | 4 (from its American pronunciation) |
| In writing | 3.6 times per million words; the 13,695th most frequent word form |
| Wrong spellings searched | none measured in search |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation and the CMU Pronouncing Dictionary; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How common is irrational?
Irrational appears 3.6 times per million words in written English, the 13,695th most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce irrational?
- /ɪˈɹæʃ.(ə.)nəl/
Irrational has 4 syllables (counted from its American pronunciation in the CMU Pronouncing Dictionary).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: LL-Q1860_(eng)-Vealhurl-irrational.wav, Wikimedia Commons (author and licence on each file's page).
Forms of irrational
- more irrational comparative
- most irrational superlative
- irrationals plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does irrational mean?
The meanings the English Wiktionary records, quoted as written there (source below).
adjective
- 1
Not rational; unfounded, nonsensical or wrong-headed.
an irrational decision
- 2
Of a real number, that cannot be written as the ratio of two integers.
The number π is irrational.
noun
- 1
A real number that can not be expressed as the quotient of two integers, an irrational number.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Irrational in Spanish, French, German and Portuguese
In the sense unfounded or nonsensical:
| Language | Words |
|---|---|
| French | irrationnel |
| German | irrational, irrationell, unvernünftig |
| Portuguese | irracional |
| Spanish | irracional |
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.
Where does irrational come from?
From Latin irratiōnālis, from ir- + ratiōnālis.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).