What does Nāsidius mean in Latin?

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

What is the genitive of Nāsidius?

The genitive singular is Nāsidiī. Nāsidius is masculine, second declension.

In classical Latin, [naːˈsɪ.di.ʊs]; in ecclesiastical (church) Latin, [naˈs̬iː.di.us].

proper noun · masculinesecond declension

Nāsidius m sg (genitive Nāsidiī or Nāsidī)

Classical[naːˈsɪ.di.ʊs]Ecclesiastical[naˈs̬iː.di.us]

Nāsĭdĭus, a,

I. name of a Roman gens.

1. L. Nasidius, a Roman knight, Cic. Phil. 7, 8, 24.—

2. An adherent of Pompey, Caes. B. C. 2, 3; Cic. Att. 11, 17, 3.—Hence, Nā-sĭdĭānus, a, um, adj., Nasidian: naves, Caes. B. C. 2, 7.