LATIN DICTIONARYLexicon Latīnum
proper nounthird declension

Senonēs

Senonēs or Sēnōnēs m pl (genitive Senonum or Sēnōnum)

Meaning

  1. a Gaulish tribe

Declension

declension
formsingularplural
nominative—Senonēs
genitive—Senonum
dative—Senonibus
accusative—Senonēs
ablative—Senonibus
vocative—Senonēs

Sĕnŏnes or Sēnōnes, um, m., = Σένονες or Σήνωνες.
I. A people in Gallia Lugdunensis, whose chief city was Agendicum, now Sens, Caes. B. G. 5, 54; 5, 56; 6, 2 sq.; 6, 44; 7, 4 al.; Plin. 4, 18, 32, § 107; Juv. 8, 234; Sil. 4, 160; Eutr. 10, 7.—In sing.: Sĕno, ŏnis, m., one of the Senones: Drappeten Senonem, Hirt. B. G. 8, 30.—
II. A people in Gallia Cisalpina, sprung from the above, Liv. 5, 35; 10, 26; Plin. 3, 15, 20, § 116.—Hence, Sĕnŏnĭcus, a, um, adj., of or belonging to the Senones: bellum, Gell. 17, 21, 21.

Origins

From Ancient Greek Σένονες (Sénones), also found as Σήνωνες (Sḗnōnes), from Gaulish *Senones, from Proto-Celtic *senos (“old”).

In the Academy Smith's classical dictionaries

Quick answers

What does Senonēs mean in Latin?
Senonēs, a proper noun, means “a Gaulish tribe”.
What is the genitive of Senonēs?
The genitive singular is Senonum. Senonēs is third declension.