What does Carthaea mean in Latin?

Carthaea, a proper noun, means “a town on the south coast of Cea”.

What is the genitive of Carthaea?

The genitive singular is Carthaeae. Carthaea is feminine, first declension.

In classical Latin, [karˈtʰae̯.a]; in ecclesiastical (church) Latin, [karˈtɛː.a].

proper noun · femininefirst declension

Carthaea f sg (genitive Carthaeae)

Classical[karˈtʰae̯.a]Ecclesiastical[karˈtɛː.a]

Carthaea, ae, f., = Καρθαία,

I. a town on the south coast of the Cycladic island Ceos or Cea, now Poles, Plin. 4, 12, 20, § 62.—

II. Hence, Carthēus and Carthēĭus, a, um, Carthœan, of Carthœa: arva, Ov. M. 10, 109: moenia = Carthaea, id. ib. 7, 368.

Borrowed from Ancient Greek Καρθαία (Karthaía).