Which term translates to 'dying' or 'fading away' in music?

The term that translates to 'dying' or 'fading away' in music is morendo. This Italian musical term is often used to indicate that a passage should be played with a sense of gradual diminishing volume and intensity, giving the effect of a gentle decline or a fading away of sound.

In practice, when musicians see morendo in a score, they understand it as a directive to make their performance increasingly softer, possibly slowing down tempo as well, to create a poignant or reflective atmosphere. This is particularly effective in conveying emotions such as sadness or tranquility.

Other terms listed, such as pesante, refer to a heavy and weighty manner of playing, while non typically means 'not' in various musical contexts and does not pertain specifically to dynamics or intensity. Ottava relates to octaves and specifies how to play notes an octave higher or lower, rather than affecting the sound's presence or absence. Therefore, morendo stands out as the most relevant and contextually appropriate term for 'dying' or 'fading away' in a musical setting.