deus.

From Old Latin deivos, from Proto-Italic *deiwos, from Proto-Indo-European *deywós. An o-stem derivative from *dyew- (“sky, heaven”), from which also diēs and Iuppiter. Details Doublet of dīvus: dẹ̄vos, -om, -ōs > dẹ̄os, -om, -ōs with regular loss of -v- before a rounded vowel; it was also lost between identical vowels, followed by contraction: *dẹ̄vẹ̄(s) > dī(s). As a result, the close -ẹ̄- escaped the regular raising to /ī/ of urban (but not dialectal) Latin, instead merging with /ē/, which itself underwent raising. The remaining genitive singular *dī was regularised to deī, while the vocative became part of the paradigm of the newly-reshaped dīvus. de- was later analogically introduced into the plural; the form diī(s) is absent from Plautus, and might have been reincorporated from a contraction of dīvī (with the same condition as before), or even be purely orthographic. Cognates with Ancient Greek Ζεύς (Zeús), Διεύς (Dieús)—archaic form of Ζεύς, Sanskrit देव (devá), Avestan 𐬛𐬀𐬉𐬎𐬎𐬀 (daēuua), Welsh duw, Lithuanian dievas, Latvian dievs, Persian دیو (div, “demon”). Despite its superficial similarity in form and meaning, not related to Ancient Greek θεός (theós) — the Latin cognate of the latter is Latin fānum.