Which term indicates a slow tempo meaning "at ease"?

The term that indicates a slow tempo meaning "at ease" is indeed adagio. In music terminology, adagio is used to describe a tempo that is slow and leisurely, often conveying a sense of relaxation or comfort. This term is commonly found in various compositions and is recognized for its expressive quality, allowing performers to convey emotion through the music at a measured, flowing pace.

Lento, another term for slow tempo, specifically means "slow" but does not carry the same sense of ease that adagio does. Allegretto is a moderately fast tempo, and vivace indicates a lively and brisk tempo, which contrasts sharply with the relaxed character of adagio. Understanding these nuances helps musicians interpret tempo markings accurately, ensuring that the expressive intent of the music is conveyed effectively.