dīum¹

Meaning

1. open sky
   Si omnino aqua non est viva, cisternae faciendae sub tectis et lacus sub dio, ex altero loco ut homines, ex altero ut pecus uti possit.If there is no running water, the cisterns must be constructed beneath covers and the lake beneath the open sky, the one for the use of the people and the other for the cattle116 BCE – 27 BCE, Marcus Terentius Varro, Rerum rusticarum 1.11.2
   Tum etiam, cum victus et cultus humanus non uti feris in propatulo ac silvestribus locis, sed domi sub tecto accurandus erat, necessarium fuit alterutrum foris et sub dio esseThen also, since man's food and clothing must be prepared, not in the open air and in the woods as for the animals, but in a home beneath a roof, it was necessary that one of the two [sexes] should live outdoors beneath the open sky4 CE – c. 70 CE, Columella, De re rustica 12.2

Declension

Origins

Nominalization of dīus. Compare also the adverb subdiū (“under an open sky”).

Meaning

1. One of the leading towns of Macedonia
2. a city in Acte

Declension

Origins

Borrowed from Ancient Greek Δῖον (Dîon).

In the Academy Smith's classical dictionaries