Reconstruction:Proto-Indo-European/dyew-

*dyew- [1]

1. to be bright
2. sky, heaven

Some derivations have undergone metathesis of the root, giving *deyw-.

• *dyḗws
• *dyutkós (“celestial, heavenly”) (+ *tek- (“to obtain, receive”))
  • Indo-Iranian: *dyukšás
    • Indo-Aryan: *dyukṣás
      • Vedic Sanskrit: द्युक्ष (dyukṣá)
• *deynos (“day”) (probably a back-formation from *deywós, interpreting *dey- as the root)
  • Balto-Slavic: *deinas, *dinas
    • Latvian: diena
    • Lithuanian: diena
    • Old Prussian: dēinā
    • Lithuanian: dėina
    • Slavic: *dьnь (see there for further descendants)
  • Germanic: *tīnaz (see there for further descendants)
  • Indo-Iranian: *dinám
    • Indo-Aryan: *dinám
      • Sanskrit: दिन (diná) (see there for further descendants)
  • Italic: *dinos
    • ⇒ Latin: nūndinus, perendinus
• *deywós
• *déywih₂
• *diwyós
• *d(i)wi-n- (possibly)
  • Armenian:
    • Old Armenian: երկինք (erkinkʿ)
• Unsorted formations:
  • Anatolian:
    • Hittite: [script needed] (šiwatt-, “day”)
    • Hittite: [script needed] (šiuniyatar, “divine image, divinity”)
  • Armenian:
    • Old Armenian: տիւ (tiw) (< *diwoh₁)
      • Armenian: տիվ (tiv)
  • Celtic: *dīyos (see there for further descendants)
  • Indo-Iranian: *dyú, *diwám, *dyáwš
    • Indo-Aryan: *dyú, *diwám, *dyáwṣ
      • Sanskrit: द्यु (dyú), दिव (divá, “sky, heaven”), द्यो (dyó, “heaven”)
    • Iranian: *dyú, *diwám, *dyáwš
      • Sogdian: ܠܝܘܐܟܟ‎ (δēwāk, “heavenly”), ܠܝܘܮܘܢ‎ (δēwγōn, “heavenly”)
      • ⇒ Persian: لیو‎ (līv, “sun”) (δēwāk > *lēwāk > lēw > lēv > līv) (perhaps) [2]

• Sihler, Andrew L. (1995) New Comparative Grammar of Greek and Latin, Oxford, New York: Oxford University Press, →ISBN
• Pokorny, Julius (1959) Indogermanisches etymologisches Wörterbuch [Indo-European Etymological Dictionary] (in German), Bern, München: Francke Verlag