LATIN DICTIONARYLexicon Latīnum
proper noun · masculinesecond declension

Zonus

Zonus m sg (genitive Zonī)
Classical[ˈzɔ.nʊs]

Meaning

  1. masculinesingularA river flowing into the Caspian Sea, mentioned by Pliny; perhaps an alternative name for the Oxus (modern Amu Darya)
    inde per Anariacos, Amardos, Hyrcanos ad ostium Zoni fluminis IIII DCCC,thence, through the territories of the Anariaci, the Amardi, and the Hyrcani, to the mouth of the river Zonus he makes four thousand eight hundred stadia,77 CE – 79 CE, Plinius Maior, Naturalis Historia 6.15.36

Declension

declension
formsingularplural
nominativeZonus—
genitiveZonī—
dativeZonō—
accusativeZonum—
ablativeZonō—
vocativeZone—

Origins

Since Pliny is quoting Eratosthenes, presumably borrowed from Ancient Greek. W. W. Tarn understands the term as a separate, native name of the Oxus, rather than a corruption of Ὦξος (Ôxos) itself, in which case it would ultimately be from a Central Asian language.

Quick answers

What does Zonus mean in Latin?
Zonus, a proper noun, means “A river flowing into the Caspian Sea, mentioned by Pliny; perhaps an alternative name for the Oxus (modern Amu Darya)”.
What is the genitive of Zonus?
The genitive singular is Zonī. Zonus is masculine, second declension.
How do you pronounce Zonus?
In classical Latin, [ˈzɔ.nʊs].