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rai

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Etymology and origin of the French word rai

Confidence
Established
Formation
Inherited
First attested
1119 Philippe de Thaon, Comput More words from the 12th century
Inherited from
Latin radius via Old French
Ultimate origin
Latin radius
Etymology tree
inherited borrowed derived
Latin radius
Catalan raig
French rai
Italian raggio
Italian razzo
Spanish rayo
English radius
Italian radio
Derivations
From the same root
French radioactif ← radius
Latin radiālis ← radius
Latin radiātus ← radius
Latin radiō ← radius
English radial ← radius

Pronunciation

Forms

rai m (plural rais)[1] Also written rais (from about 1380).[2][3]

Etymology

It is inherited from Old French rai, inherited from Latin radius (“rod, spoke of a wheel, ray of light”).[4][2][5][6] Rey calls the Latin word of uncertain origin; a special use of it gave the learned doublet radius.[2][1]

Cognate with Romanian rază, Italian raggio, Occitan rai, Catalan raig, Spanish rayo and Portuguese raio.[7] Wiktionary notes that it is unrelated to raie1.[1]

Earliest recorded meaning

Philippe de Thaon uses it in his Comput (1119) for a ray of light.[4][2]

Semantic evolution

Its derivative rayon1 (1474) competed with it and drove it out in the sense “beam of light”, so that rai became poetic and archaic, though modern prose has taken it up again, chiefly for a beam standing out against the dark, as in un rai de lumière.[2]

Since 1200–1220 it has named the spoke of a wooden wheel,[4][2] and in heraldry the rays of the carbuncle or the points of a star (1671).[4][2][7] Architecture has rai de cœur (1676), a moulding of pointed heart-shaped leaves alternating with spearheads.[2]

Timeline

  • 1119 – “Ray of light” in Philippe de Thaon's Comput.[4][2]
  • 1200–1220 – “Spoke of a wheel” in the Pseudo-Turpin.[4][2]
  • 1474 – The derivative rayon (reon du soleil) appears.[2]
  • 1671 – Pomey's heraldic rais d'escarboucle.[4]
  • 1676 – Rai de cœur in architecture.[2]

Meanings

Noun

  1. (dated or literary) A ray or beam of light: un rai de soleil.[7][4]
  2. (heraldry) Each of the rays from the centre of a carbuncle, or each point of a star.[7][5]
  3. (technical) A spoke of a wooden wheel.[7][4]

Word family

  • radiation
  • radieux
  • irradier
  • rai-de-cœur
  • Latin radius

Usage notes

Rai sounds the same as raie1 and rets.[7]

References

  1. ^ a b c d Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g h i j k l Rey, Alain, ed. (1992), Dictionnaire historique de la langue française, Paris: Le Robert
  3. ^ Rey, Alain, ed. (2005), Le Grand Robert de la langue française, electronic version, Paris: Le Robert
  4. ^ a b c d e f g h i 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
  5. ^ a b Guilbert, Louis; Lagane, René; Niobey, Georges, eds. (1971–1978; 1989), Grand Larousse de la langue française, Paris: Larousse
  6. ^ Wartburg, Walther von, et al. (1922–2002), Französisches Etymologisches Wörterbuch, 25 vols., Bonn / Leipzig / Basel: Klopp / Teubner / Zbinden, p. 10, 21b
  7. ^ a b c d e f Rey-Debove, Josette; Rey, Alain, eds. (2007), Le Petit Robert de la langue française, Paris: Le Robert

Related etymologies

Cite this entry

“Rai.” Etymologically, 14 Nov. 2026, etymologically.com/fr/rai. Accessed 15 Nov. 2026.

Last edited on . ·