peräisinillä
Peräisinillä is a term encountered in some Finnish scholarly texts dealing with provenance and origin. It is not a standard dictionary entry; rather it appears as a specialized form used to indicate that something comes from particular sources or origins. The base adjective peräisin means "originating from" or "derived from." The form peräisinillä is formed by combining this adjective with a locative suffix, a pattern seen in some archaic or dialectal Finnish constructions to signal "on/at the origins of" or "from the origins of" a set of items or sources.
Because this usage is not common in everyday Finnish, it may appear only in historical, ethnographic, or