pääasialainen
Pääasiallinen is a Finnish word that translates to "main," "principal," or "primary" in English. It is used to describe the most important or fundamental aspect of something. For example, one might refer to the pääasiallinen syy (main reason) or the pääasiallinen tavoite (primary goal).
The word is derived from "pää," meaning "head," which implies a sense of being at the top
In legal and official documents, the term pääasiallinen can denote the principal party or the main clause