Karjala.

The traditional theory says that the name is simply karja + -la. In modern Finnish, karja means “livestock, cattle”; one explanation says that the name Karjala originally meant “pasture” (and karjalainen (“Karelian”) originally meant “cattle herder”). Another explanation points out that the Finnish word was borrowed from Proto-Germanic *harjaz (“army”), and this original meaning “army” might be the one seen in Karjala. Alternatively, Saarikivi (2024) has remarked that the other forms of the name, notably Kariela found in Tver Karelian, are more likely to be primary (rather than secondary due to e.g. Russian influence); the oldest form found in Slavic corresponds to Корела (Korela). Most likely, this name originally referred to a smaller region or even a town, such as Käkisalmi (Priozersk, first mentioned in historical records as Old Novgorodian Корѣла (Korěla) since 1143). The name could derive a given name like *Karie, *Karei (possibly akin to karkea, compare Livvi karei), or from an old Orthodox given name, in either case with -la. The place name is first attested in Latin text as Cariali in 1257. For the surname, compare Karjalainen.

karja- + -la. May be named after Karjakoski (probably karja + koski), a village near Mynämäki, perhaps because it was the village from which settlers arrived in Karjala (the village after which the municipality was named).