What term is defined as the quality given to a sound by its overtones?

The term that defines the quality given to a sound by its overtones is timbre.

Here's why:

* Timbre refers to the unique sound quality of a musical instrument or voice.

* Overtones are higher-frequency sounds that are produced alongside the fundamental frequency (the main pitch).

* The specific combination and intensity of overtones determine the unique timbre of a sound.

For example, a violin and a flute might play the same note (fundamental frequency), but they will sound different because they produce different overtones.