LATIN DICTIONARYLexicon Latīnum
proper noun · masculinesecond declension

Aquīnius

Aquīnius m sg (genitive Aquīniī or Aquīnī)
Classical[aˈkʷiː.ni.ʊs]Ecclesiastical[aˈkʷiː.ni.us]

Meaning

  1. a Roman nomen gentile, gens or "family name" famously held by
  2. Aquinius, a Roman poet

Declension

declension
formsingularplural
nominativeAquīnius—
genitiveAquīniī
Aquīnī		—
dativeAquīniō—
accusativeAquīnium—
ablativeAquīniō—
vocativeAquīnī—

Ăquīnĭus (or Ăquīnus), i, m.,
I. an inferior poet, friend of Cicero: Mihi fuit cum Aquinio amicitia, Cic. Tusc. 5, 22, 63.—As an appell.: Caesios, Aquinos, Cat. 14, 18.

Quick answers

What does Aquīnius mean in Latin?
Aquīnius, a proper noun, means “a Roman nomen gentile, gens or "family name" famously held by”.
What is the genitive of Aquīnius?
The genitive singular is Aquīniī. Aquīnius is masculine, second declension.
How do you pronounce Aquīnius?
In classical Latin, [aˈkʷiː.ni.ʊs]; in ecclesiastical (church) Latin, [aˈkʷiː.ni.us].