绝缘
jué yuán · HSK 7
to insulate
🔌 绝 cut-off + 缘 tie = sever every tie; in wiring it means insulate a wire
绝 means to sever or break off completely; 缘 is a bond, tie, or fated connection. Together: cut off all connection. For electricity that is exactly what insulation does — it breaks the connection so current cannot pass.
绝 — silk 纟 + 巴 (phonetic-ish, knife cutting threads)
绝 originally depicted cutting silk threads with a knife, conveying the idea of severing or cutting off completely. From this concrete sense it extended to mean 'to break off,' 'exhausted,' and figuratively 'absolute' or 'extreme.' The simplified form replaced the older right-hand component with 巴.