Where does “Byun” come from?

Byun (English) comes from Korean 변, from Middle Chinese 變.

Ancestry of “Byun”, step by step

StepLanguageWordMeaning
1Korean변jargon, argot, lingo
2Middle Chinese變—
Every word from Middle Chinese 變 →Every word from Korean 변 →
Byun — Etymology, Origin & Word History | Etymology Explorer