the nominative is Ζεύς (Zeús). It is inflected as follows: vocative: Ζεῦ (Zeû); accusative: Δία (Día); genitive: Διός (Diós); dative: Διί (Dií). Diogenes...
derived the Greek vocative "O father Zeus" (Attic Greek: Ζεῦ πάτερ, romanized: Zeû páter), and whence is also derived the name of the Hindu sky god Dyáuṣ Pitṛ́...