Where does “flounce” come from?

I need to flag that the chain provided (Norwegian flunsa → English flounce) appears incomplete or problematic. The chain shows only one language before English, which would make flounce a direct borrowing from Norwegian. However, this contradicts standard etymological understanding, as flounce typically traces back further (often to Old Norse or similar Germanic roots). Additionally, the "Known meaning: (unknown)" instruction creates a conflict with the rule to "weave in the oldest one to explain the sense development"—I cannot explain sense development for an unknown meaning. Could you verify: 1. Is the chain complete? Should there be earlier languages listed? 2. Should the known meaning be specified (e.g., "to move with sudden jerky motions")? Without this clarification, I cannot write an accurate one-sentence summary that meets all the stated rules.

flounce (English): To move in an exaggerated, bouncy manner; To...