kertaluontoisesti
Kertaluontoisesti is a Finnish adverb that translates to "once," "singularly," "uniquely," or "on a one-off basis" in English. It describes an event or action that happens only once, not to be repeated. The term emphasizes the exceptional or non-recurring nature of something.
For example, a special concert that is advertised as "kertaluontoisesti" implies it will not be part of