General movement:
* Vibration: This is the most common and accurate term for the back-and-forth motion of a string.
* Oscillation: Similar to vibration, but often implies a more regular, periodic movement.
* Fluctuation: This suggests a more irregular or unpredictable movement.
Specific movements:
* Waving: This describes a gentle, undulating motion like a wave.
* Rippling: This suggests a series of small waves traveling along the string.
* Twirling: This implies a circular or helical movement.
* Swaying: This describes a slow, gentle back-and-forth motion.
* Snapping: This refers to a sudden, sharp movement, often associated with breaking.
Other options:
* Motion: This is a very general term, but it can be used to describe any movement of the string.
* Dynamics: This refers to the changes in volume, intensity, and speed of the string's movement.
Ultimately, the best word to describe the movement of a string depends on the specific context. Consider what kind of movement you're trying to convey and choose the word that best captures that meaning.