Finnish word perusasia comes from Finnish asia, Finnish perus-

Detailed word origin of perusasia

Dictionary entry	Language	Definition
asia	Finnish (fin)	Court case. Issue, matter, affair, concern, business, subject, case.
perus-	Finnish (fin)	Basic, elemental, fundamental, rudimentary, normal, typical, average. Primal.
perusasia	Finnish (fin)	Essential (something basic, elementary or indispensable).

Words with the same origin as perusasia