Which musical term indicates a gradual decrease in volume?

The term that indicates a gradual decrease in volume is “decrescendo.” This term, often abbreviated as "decresc." in musical notation, instructs performers to gradually reduce the loudness of the music over a designated span of time. The effect of a decrescendo creates a sense of fading away, offering expressive depth to the performance.

Comparatively, the other terms refer to different musical concepts. “Forte” signifies a loud dynamic level, indicating to perform the music with strength and volume. “Morendo” suggests a dying away or softening of sound, but primarily refers to the manner of fading rather than a specific instruction regarding dynamic measurement. “Staccato” refers to a style of playing where notes are sharply separated rather than connected smoothly, and has no direct relationship with volume changes. Understanding these distinctions highlights the specific role of decrescendo within musical dynamics.