Which term in music tempo is typically used for a slow and soft passage?

The term that is typically used for a slow and soft passage in music is "adagio." This term specifically indicates a tempo that is slower than moderate, often conveying a gentle and expressive character. It allows for a sense of calmness and introspection, making it suitable for pieces that require a delicate touch.

While the other terms also refer to musical dynamics or tempo, they do not convey the same slow and soft nuance as "adagio." "Piano," for instance, means soft but does not specify tempo. "Fortissimo" indicates a very loud dynamic, which stands in direct contrast to the softness implied in "adagio." "Moderato" refers to a moderate tempo, faster than "adagio," and does not capture the slow quality that "adagio" does. Therefore, "adagio" is the best choice for describing a passage that is both slow and soft.