What does Rschovia mean in Latin?

Rschovia, a proper noun, means “Rzhev (a town in Tver Oblast, Russia)”.

What is the genitive of Rschovia?

The genitive singular is Rschoviae. Rschovia is feminine, first declension.

In classical Latin, [ˈrskʰɔ.wi.a]; in ecclesiastical (church) Latin, [ˈrskɔː.vi.a].

proper noun · femininefirst declension

Rschovia f sg (genitive Rschoviae)

Classical[ˈrskʰɔ.wi.a]Ecclesiastical[ˈrskɔː.vi.a]

Medieval LatinfemininesingularRzhev (a town in Tver Oblast, Russia)
Hic Ducatus Rschouiæ in quo prædictus fluuius fontes ſuos habet, latißimè extenditur, ab hocq́; Dux Moſchouiæ titulum ſibi vſurpat, & Ducem Rschouiæ se appellat.This Duchy of Rzhev, in which the aforementioned river has its sources, is very widely extended, and from it the Duke of Muscovy usurps its title for himself, and calls himself the Duke of Rzhev.1578, Alexander Guagnini, Sarmatiae Europeae descriptio, quae Regnum Poloniae, Lituaniam, Samogitiam, Russiam, Masouiam, Prussiam, Pomeraniam, Liuoniam, et Moschouiae, Tartariaeque partem complectitur [Description of European Sarmatia, Which Encompasses the Kingdom of Poland, Lithuania, Samogitia, Russia, Mazovia, Prussia, Pomerania, Livonia, Muscovy, and Part of Tartary], Omnium regionum, Moschouiae Monarchae subiectarum, Tartarorumque Campestrium, Arcium, Ciuitatum praecipuarum, Morum denique gentis, Religionis, et consuetudinis vitae sufficiens, et vera descriptio [A sufficient and true description of all the regions subject to the monarch of Muscovy, the fields of the Tartars, the fortresses, particular cities, and then the customs of the people, the religion, and habits of life], folio 7v:

Borrowed from Polish Rżow.