What does Rabīrius mean in Latin?

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

What is the genitive of Rabīrius?

The genitive singular is Rabīriī. Rabīrius is masculine, second declension.

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

proper noun · masculinesecond declension

Rabīrius m sg (genitive Rabīriī or Rabīrī)

Classical[raˈbiː.ri.ʊs]Ecclesiastical[raˈbiː.ri.us]

Răbīrĭus, i, m.,

I. the name of a Roman gens. Thus,

1. C. Rabirius, a tribune of the people; and,

2. C. Rabirius Postumus, a knight; both of them defended by Cicero in orations still extant.—

3. An indifferent philosophical writer, Cic. Ac. 1, 2, 5. —

4. An excellent poet, Ov. P 4, 16, 5; Quint. 10, 1, 90. — Hence,

II. Răbīrĭānus, a, um, adj., of or belonging to a Rabirius, Rabirian: domus, Cic. Att. 1, 6, 1.