What does Sertōrius mean in Latin?

Sertōrius, a proper noun, means “a Roman nomen gentile, gens or "family name" famously held by”.

What is the genitive of Sertōrius?

The genitive singular is Sertōriī. Sertōrius is masculine, second declension.

In classical Latin, [sɛrˈtoː.ri.ʊs]; in ecclesiastical (church) Latin, [serˈtɔː.ri.us].

proper noun · masculinesecond declension

Sertōrius m sg (genitive Sertōriī or Sertōrī)

Classical[sɛrˈtoː.ri.ʊs]Ecclesiastical[serˈtɔː.ri.us]

Sertōrĭus, ii, m.,

I. a proper name. So, Q. Sertorius, a general of Marius, who maintained himself for a long while in Spain against the partisans of Sylla, but was finally assassinated by Perperna, Liv. Epit. 90; Vell. 2, 25, 3; Flor. 3, 22; Luc. 2, 549; Cic. Brut. 48, 180; id. Imp. Pomp. 4, 9; id. Mur. 15, 32; Sall. H. 1, 54 sqq. Dietsch.—Hence, Sertōrĭānus, a, um, adj., of or belonging to Sertorius, Sertorian: bellum, Cic. Phil. 11, 8, 18; Flor. 3, 22: arma, Sen. Ep. 94, 64: milites, Cic. Verr. 2, 5, 28, § 72; 2, 5, 56, § 146; 2, 5, 58, § 143: duces, id. Imp. Pomp. 8, 21: tempora, id. Agr. 2, 30, 83.

From *sertor + -ius, from serō (“to link”) + -tor (“-er”).