絃

Phono-semantic compound:

糸 (사, silk thread) — semantic component, indicating fiber/thread.

玄 (현, dark/black; mysterious) — phonetic component, also contributing meaning “subtle, deep.”

Thus: a “thread with depth/subtlety,” i.e. a musical string.

Originally used for string of instruments.

絃樂 (현악) — string music, strings section

絃歌 (현가) — singing to the accompaniment of a string instrument

絃琴 (현금) — stringed instrument (zither, harp, etc.)

In most regions (China, Japan), replaced by the simplified form 弦 (also used historically as an interchangeable form).

Korea preserves the traditional form 絃 in some compounds.