This is the 452nd most frequent Finnish word.
viron
"Viron" is the genitive form of "Viro," meaning "Estonia" in Finnish.
Here, 'viron' is the partitive form of 'viro,' used to specify 'Estonian language'.
Opiskelin viron kieltä viime vuonna.
I studied the Estonian language last year.
In this context, 'Viron' acts as the genitive form of 'Viro,' indicating possession, i.e., forests of Estonia.
Kävimme matkalla Viron kauniissa metsissä.
During the trip, we visited Estonia's beautiful forests.
Here, 'Viron' is again the genitive form, describing literature originating from Estonia.