fou

\fu\

/\fu\/ adj

By · According to Wiktionary data (CC BY-SA) ·

The verdict

“fou” is a regularly-used French word, ranked #1,063 in French word frequency and used as an adjective.

#1,063
frequency rank, French
3
letters
20
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Qualifie une personne qui a perdu la raison, qui est atteinte d’aliénation mentale.

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

fou vs ft
33% similar
fou vs Fs
0% similar
fou vs FP
0% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for fou
PropertyValue
Headwordfou
LanguageFrench
Part of speechAdjective
IPA\fu\
Letters3
Frequency rank#1,063
Misspellings tracked0
Confusable pairs20
SourceWiktionary (kaikki.org)

Where “fou” sits in French frequency

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right). fou lands here:

#1#100#1K#10K#100K
← used constantlyrarely used →

Scale is logarithmic (each tick is 10× rarer). Source: FrequencyWords open word-frequency list.

Spelling & Dictionary Insight

The French entry for fou is 3 letters long, classified as an adjective, and transcribed in the International Phonetic Alphabet as \fu\. Corpus data places it at rank #1,063 in overall French word frequency, indicating it appears regularly in written and spoken text. Wiktionary records 12 distinct senses for this headword, so context determines which meaning a reader should apply.

We couldn't generate a plausible misspelling set for fou, and the word's spelling is regular enough that our generator found nothing worth flagging. It also participates in 20 confusable-pair relationships, "ft", "Fs", "FP", and more, a pairing that trips writers up because the two words share enough sound or shape to blur together.

This headword's origin isn't recorded in our source data, so any spelling logic here comes from how the word's sounds map to letters, not a documented origin story. The correct French form is fou, spelled F-O-U.

Definition

  1. 1
    Qualifie une personne qui a perdu la raison, qui est atteinte d’aliénation mentale.
  2. 2
    Qualifie une personne qui perd patience par les choses qu’on lui a dites, qu’on lui a faites mal à propos.
  3. 3
    Qualifie une personne qui fait ou qui dit des extravagances, qui commet toutes sortes de maladresses.
  4. 4
    Qualifie tout ce qui est contraire à la raison, à la prudence, à la modération.
  5. 5
    Qualifie une personne hors d’elle, passionnée.
  6. 6
    Qualifie quelque chose de stupide.
  7. 7
    Qualifie quelque chose de surprenant.
  8. 8
    Qualifie quelque chose d’exagéré, de démesuré, d’énorme.
  9. 9
    Qualifie un mécanisme dérangé.
  10. 10
    Qualifie une roue, une poulie, un tambour etc. ne transmettant pas de force motrice et tournant librement autour de son axe.
  11. 11
    Extrêmement gai, badin, enjoué.
  12. 12
    Qui manque d’ordre, qui suit un comportement apparemment capricieux.

Synonyms

agité du bocalaliénéavoir été bercé trop près du murazimutébargebarjebarjobarjotbotchbrindezinguecabourdcabourdascaluccinglécintréchtarbédéjantédémentdétraquédérangédéséquilibrédinguedingofadafadolifêléfoldingofoldinguefou à lierfoulekfrappadinguegelégivrégogolguedininsanejobardjobastreloufloufetinguelouftinguemaboulmarteaunévropathenévrosénévrotiqueoufperturbépété par la geléepsychasthéniquepsychopathepsychotiquesinoquesiphonnétabanardtarétcharbétimbrétoctoctoc-toctoquézinzinzonézonzonaccroamoureuxdingodingueférufondumarteaumordupassionnéaberrantabsurdedéraisonnableinsenséstupidebizarreextravagantfantasquesurprenanténorme

This word in other languages

crazy(English)loco(Español)wahnsinnig(Deutsch)louco(Português)

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 French corpus, MIT). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "fou"?
"fou" is spelled F-O-U. The IPA pronunciation is \fu\.
What does "fou" mean?
As an adjective, "fou" means: Qualifie une personne qui a perdu la raison, qui est atteinte d’aliénation mentale.
What words are commonly confused with "fou"?
"fou" is commonly confused with "ft", "Fs", "FP". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "fou"?
The IPA (International Phonetic Alphabet) transcription for "fou" is \fu\. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What language does "fou" come from?
"fou" is a French word. PlainSpell covers definitions, pronunciations, and spelling data across English, Spanish, Portuguese, French, and German.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Using “fou”

The practical upshot for anyone who landed here from a spell-check.

  • The one correct French spelling is F-O-U - every other letter order is a misspelling in standard orthography.
  • Say it as \fu\ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
  • Don't mix it up with “ft” - see the side-by-side comparison. fou vs ft
  • Browse more French words and confusable pairs in the same reference. French words
Data Source

Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list FrequencyWords open word-frequency list