I might have written about this before but: to people who are weirded out Modern Greeks call Zeus Δίας (Dias).
The original name of Zeus, first attested in Mycenaean Greek Linear B scripts (1400-1200 BC), was di-we, di-wo, from the possible Proto-Hellenic form *dzeus, from possible PIE root being *dewos, meaning “god”. That d-strong form in Mycenaean was later retained better in the secondary forms of the noun, meaning the cases apart from the nominative.
Nominative: ὁ Ζεύς (o Zeus)
Genitive: τοῦ Διός (tou Dios)
Dative: τῷ Διῐ́ (to Dii)
Accusative: τὸν Δίᾰ (ton Dia)
Vocative: ὦ! Ζεῦ (oh Zeu)The theorized z-including form *dzeus in Proto-hellenic survived better in some Greek dialects but even less so in others:
- Δάν (Dán) — Aeolic
- Δεύς (Deús) — Boeotian
- Ζάς (Zás) — Laconian
- Ζάν (Zán), Ζάς (Zás) — Doric
- Ζήν (Zḗn) — poetic
- Θιός (Thiós), Σιός (Siós) — Boeotian, Ionic
- Τάν (Tán) — Cretan
As for Modern Greek, it has more often retained words through their secondary rather than their nominative cases, with the accusative case being the most common, like here.