oleellisten
The term "oleellisten" is the genitive plural form of the Finnish word "oleellinen," which translates to "essential" or "fundamental" in English. Therefore, "oleellisten" refers to "of the essential" or "of the fundamental things." In Finnish grammar, the genitive case is used to indicate possession, origin, or relationship, and the plural form indicates that there are multiple essential items or concepts being referred to.
When encountered in a Finnish text, "oleellisten" would typically be part of a phrase describing something related