Where does “Keski-Pohjanmaa” come from?

Keski-Pohjanmaa (Finnish) comes from Finnish Pohjanmaa, from Finnish mää, from Finnish -inen, from Finnish -uus, from Proto-Finnic -uc — -ness, -hood.

Ancestry of “Keski-Pohjanmaa”, step by step

StepLanguageWordMeaning
1FinnishPohjanmaaOstrobothnia
2Finnishmääbaa; I
3Finnish-inen-like, -ous, -y; -en; Creates adjectives from...
4Finnish-uusForms nouns from adjectives, expressing a quality
5Proto-Finnic-uc-ness, -hood
Every word from Proto-Finnic -uc →Every word from Finnish -inen →Every word from Finnish -uus →