What does Nō̆rēïa mean in Latin?

Nō̆rēïa, a proper noun, means “a town in Noricum; a town of the Carni”.

What is the genitive of Nō̆rēïa?

The genitive singular is Nō̆rēïae. Nō̆rēïa is feminine, first declension.

In classical Latin, [nɔˈreː.i.a]; in ecclesiastical (church) Latin, [noˈrɛː.i.a].

proper noun · femininefirst declension

Nō̆rēïa f sg (genitive Nō̆rēïae)

Classical[nɔˈreː.i.a]Ecclesiastical[noˈrɛː.i.a]

a town in Noricum
Boiosque, qui trans Rhenum incoluerant et in agrum Noricum transierant Noreiamque oppugnabant, receptos ad se socios sibi adsciscunt.and they admit to their party and unite to themselves as confederates the Boii, who had dwelt on the other side of the Rhine, and had crossed over into the Norican territory, and assaulted Noreia.100 BCE – 44 BCE, Julius Caesar, Gallic War 1.5
a town of the Carni

Nŏrēïa, ae, f.,

I. a town in Noricum, now prob. Neumarkt, Caes. B. G. 1, 5; Plin. 3, 19, 23, § 131.