Etymologically

Etymology and origin of the French word flou

Confidence
Disputed
Formation
Inherited
First attested
c. 1200 Renaut de Montauban More words from the 12th century
Inherited from
Latin flavus via Old French
Ultimate origin
Latin flāvus
Etymology tree
inherited borrowed derived
Latin flāvus
French flou
From the same root
Latin flāveō ← flāvus
Latin flāvēscō ← flāvus

Pronunciation

Forms

flou (feminine floue, masculine plural flous, feminine plural floues)[1] Old French flo and flou, feminine floe.[2][3][4]

Etymology

It is inherited from Old French flou (also flo), taken up again as a painters' term in 1676 after it had dropped out of use.[2][3] The TLFi, the FEW, Bloch–Wartburg and Rey hold that it is inherited from Latin flāvus (“yellow”), which must already have come to mean “faded, withered” in Latin, as the verb flāvēscō (“to wither”) shows, and hence “weak, languid”;[5][6][7][2] Old French floe also meant “yellow”.[5][6][7][2] Rey calls the change of sense a farming metaphor.[2]

Wiktionary instead derives it from Frankish *hlāo (“lukewarm, mild”), from Proto-Germanic *hlēwaz (“warm, lukewarm”), and gives the Latin derivation as an alternative.[1] Diez, cited by Littré, took the Old French word from Flemish flauw (“weak”), and Scheler wondered whether the painters' word came from Latin fluidus (“flowing”).[4] Bloch and Wartburg hold, on the contrary, that German flau and the Dutch word come from French.[7]

Earliest recorded meaning

About 1200, in Renaut de Montauban, Old French flo described land as waste and deserted; by 1274 Adenet le Roi used it of a person tired out.[5][2]

Semantic evolution

Old French used the word of wilted, limp and weak things;[2][4] flou “slender, delicate” is still in Villon.[2][4] It then fell out of use, and Félibien wrote in 1676 that it was an old word once used in painting for the softness and delicacy of a work.[5][3] The art term spread in the 18th century: Diderot wrote of a genre flou in 1765, and peindre flou “to paint in a soft, light manner” is recorded in 1771.[5][2]

From 1855 (the Goncourts) the adjective meant “indistinct, blurred”, and as a noun le flou meant vagueness from 1904 (Barrès).[5][2] In the 20th century it became the term for a deliberate softening of focus in photography and cinema, and about 1970 sous-ensemble flou translated the English mathematical term fuzzy set.[2] The derivative fluet “slender”, an altered form of flouet (about 1450), is no longer felt as related to it.[2][7]

Timeline

  • c. 1200 – Flo “waste, deserted” in Renaut de Montauban.[5]
  • 1274 – Adenet le Roi uses it for “tired, worn out”.[5]
  • c. 1450 – The derivative flouet appears.[2]
  • 1676 – Félibien records it as an old painters' word.[5][2]
  • 1765 – Diderot uses it in his Salon.[5]
  • 1855 – The Goncourts use it for “indistinct”.[5]
  • 1904 – Barrès uses the noun le flou “vagueness”.[5]
  • c. 1970 – Sous-ensemble flou renders English fuzzy set.[2]

Meanings

Adjective

  1. (art) With softened, blended outlines.[8][9]
  2. Blurred, out of focus: une photo floue.[8][9]
  3. Loose, not close-fitting: une robe floue.[8]
  4. (figurative) Vague, uncertain, lacking precision.[8][9]

Noun

  1. Blurriness;[8][2] (photography, cinema) a deliberate loss of sharpness in the image;[8][2] flou artistique, such an effect used for its beauty.[8][2]
  2. (figurative) Vagueness, lack of clarity: laisser les choses dans un flou artistique.[8][5]

Word family

  • fluet

References

  1. ^ a b c Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g h i j k l m n o p q r Rey, Alain, ed. (1992), Dictionnaire historique de la langue française, Paris: Le Robert
  3. ^ a b c Rey, Alain, ed. (2005), Le Grand Robert de la langue française, electronic version, Paris: Le Robert
  4. ^ a b c d Littré, Émile (1873–1877), Dictionnaire de la langue française, 4 vols. and supplement, Paris: Hachette
  5. ^ a b c d e f g h i j k l m Trésor de la langue française informatisé (2004), ATILF – CNRS & Université de Lorraine, atilf.fr/tlfi; electronic version of Imbs, Paul; Quemada, Bernard, eds. (1971–1994), Trésor de la langue française, Paris: CNRS / Gallimard
  6. ^ a b Wartburg, Walther von, et al. (1922–2002), Französisches Etymologisches Wörterbuch, 25 vols., Bonn / Leipzig / Basel: Klopp / Teubner / Zbinden, p. 3, 615a
  7. ^ a b c d Bloch, Oscar; Wartburg, Walther von (1989), Dictionnaire étymologique de la langue française, 8th ed., Paris: Presses universitaires de France
  8. ^ a b c d e f g h Rey-Debove, Josette; Rey, Alain, eds. (2007), Le Petit Robert de la langue française, Paris: Le Robert
  9. ^ a b c Guilbert, Louis; Lagane, René; Niobey, Georges, eds. (1971–1978; 1989), Grand Larousse de la langue française, Paris: Larousse

Related etymologies

  • malle · also from Frankish
  • houx · also from Frankish
  • halle · also from Frankish
  • gué · also from Frankish
  • canif · also from Frankish
  • haïr · also from Frankish
  • étai · also from Frankish
  • barguigner · also from Frankish
Cite this entry

“Flou.” Etymologically, 11 Nov. 2026, etymologically.com/fr/flou. Accessed 12 Nov. 2026.

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