iubar

Uncertain:

• From Proto-Italic *djuβās, from Proto-Indo-European *dyew-bʰeh₂-es- (“bringing the light of daytime”, literally “sky-shining”), from *dyew- (“sky, heaven”) (whence Latin diēs (“day”)) and *bʰeh₂- (“to shine”) (whence Ancient Greek φάος (pháos, “light”)).
• From Proto-Indo-European *Hyéwdʰ-r̥ from the root *Hyewdʰ-, from which also iubeō, directly cognate to Ancient Greek εἶθαρ (eîthar, “at once”).

• (Classical Latin) IPA^(key): [ˈjʊ.bar]
• (modern Italianate Ecclesiastical) IPA^(key): [ˈjuː.bar]

iubar n (genitive iubaris); third declension

1. radiance of celestial bodies, sunshine, light, rays of light, brightness; (less exactly) dawn, morning
   • 239 BCE – 169 BCE, Ennius, Annales 571–572:

     interea fugit albus iubar Hyperionis cursum;
     inde patefecit radiis rota candida caelum

     meanwhile the white radiance of Hyperion fled its course;
     thence the bright-shining wheel uncovered the sky with its rays

   • 29 BCE – 19 BCE, Virgil, Aeneid 4.129-130:

     Ōceanum intereā surgēns Aurōra relīquit.
     It portīs iubare exortō dēlēcta iuventūs [...].

     Meanwhile Aurora, rising, departs from Oceanus. [Then,] with Dawn’s radiance having shone forth, chosen youth go out the [city] gates [...].

2. (figuratively) a splendid appearance, glory, splendor

Third-declension noun (neuter, imparisyllabic non-i-stem).

• “iubar”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• De Vaan, Michiel (2008) Etymological Dictionary of Latin and the other Italic Languages (Leiden Indo-European Etymological Dictionary Series; 7), Leiden, Boston: Brill, →ISBN
• Willi, Andreas (2001) “Lateinisch iubēre, griechisch εὐϑύς und ein indogermanisches Rechtskonzept”, in Historische Sprachforschung‎^[1] (in German), volume 114, number 1. H., pages 117–146