What does Dīnarchus mean in Latin?

Dīnarchus, a proper noun, means “A Greek orator, imitator of Demosthenes”.

What is the genitive of Dīnarchus?

The genitive singular is Dīnarchī. Dīnarchus is masculine, second declension.

proper noun · masculinesecond declension

Dīnarchus m sg (genitive Dīnarchī)

Dīnarchus, i, m., = Δείναρχος,

I. an Attic orator, an imitator of Demosthenes, Cic. de Or. 2, 23, 94; id. Brut. 9, 36.

Borrowed from Ancient Greek Δείναρχος (Deínarkhos).