This is the 807th most frequent Czech word.
ruskem
The Czech word "ruskem" means "by Russia" or "through Russia" (instrumental case of "Rusko," meaning Russia).
Here 'Rusko' indicates the country (Russia), and 'přes Rusko' describes traversing through it.
Cestoval jsem z Prahy do Moskvy přes Rusko.
I traveled from Prague to Moscow through Russia.
In 'Ruskem,' it is the instrumental case of 'Rusko,' used here to indicate 'with or by Russia' in the context of bordering territories.
Na mapě najdete hranici mezi Polskem a Ruskem.
On the map, you will find the border between Poland and Russia.
Here 'Ruskem' as the instrumental case shows the origin or medium through which the culture is spreading.