弦

The glyph centers on the concept of a stretched line under tension:

• Music: The functional string of an instrument (e.g., 琴 or 瑟) capable of producing sound through vibration.
• Astronomy/Shape: A crescent or bow-shape, most commonly referring to the moon in its first or last quarter (弦月).
• Geometry: A chord; a straight line connecting two points on a curve. (Note: While some sources list "hypotenuse," it generally refers to the chord of a circle in technical contexts.)

To distinguish from other terms for string or thread:

• 弦 (xián): Defined by function and tension (musical strings, bowstrings, geometric chords).
• 絲 (sī): Defined by material (silk, fine fiber, thread).
• 繩 (shéng): Defined by utility or bulk (rope, cord used for binding or measuring).

Fanqie reading: 胡田; Tang-period reading: *hen. Semantic variant: U+7D43.