LATIN DICTIONARYLexicon Latīnum
proper noun · masculinethird declension

Sīris1

Sīris m sg (genitive Sīris)

Meaning

  1. a river in Lucania that flows into the Ionian Sea, now the river Sinni
    similiter est inter Sirim et Acirim Heraclea, aliquando Siris vocitata.77 CE – 79 CE, Plinius Maior, Naturalis Historia 3.97.6

Declension

declension
formsingularplural
nominativeSīris—
genitiveSīris—
dativeSīrī—
accusativeSīrim—
ablativeSīrī—
vocativeSīris—

Sīris, is, m., = Σίρις.
I. The name of a branch of the Nile in Ethiopia, Plin. 5, 9, 10, § 54; Prisc. Perieg. 212.—
II. A river in Italy, Plin. 3, 11, 15, § 97.—
III. A name for Heraclea in Magna Graecia, Plin. 3, 11, 15, § 97.

Origins

From Ancient Greek Σῖρις (Sîris).

In the Academy Smith's classical dictionaries

proper noun · femininethird declension
Sīris2
Sīris f sg (genitive Sīris)

Meaning

  1. A city of Magna Graecia situated at the mouth of the river with the same name

Declension

declension
formsingularplural
nominativeSīris—
genitiveSīris—
dativeSīrī—
accusativeSīrim—
ablativeSīrī—
vocativeSīris—
locativeSīrī—

Origins

From Ancient Greek Σῖρις (Sîris).

In the Academy Smith's classical dictionaries

Quick answers

What does Sīris mean in Latin?
Sīris, a proper noun, means “a river in Lucania that flows into the Ionian Sea, now the river Sinni”.
What is the genitive of Sīris?
The genitive singular is Sīris. Sīris is masculine, third declension.