jäkkeä

I couldn’t locate a widely recognized definition for “jäkkeä” in standard sources. Could you specify whether jäkkeä refers to a real concept in a particular field (for example language, culture, geography) and, if so, where it is used? If you intended jäkkeä as a fictional or placeholder term for a wiki article, I can draft a neutral stub in under 300 words. Please indicate which you prefer.