Refers to strings made from animal intestines (catgut) or similar material, used for musical instruments, surgical sutures, or sports rackets. The term is somewhat technical.
The violin string broke, so I replaced it with a new one.
Old tennis rackets used catgut strings.
糸 means 'thread' or 'yarn' in general, not specifically a musical string. 弦線 is a specialized type of string.
Standard kanji spelling for 'catgut' or 'string' (e.g., for musical instruments).
Variant kanji form; 絃 is an older character for 'string' and is less common in modern usage.
Compound of 弦 (げん, 'string') and 線 (せん, 'line' or 'wire'), literally 'string line'. The term likely arose to distinguish catgut strings from other types of strings or wires.