What term describes the gradual movement of soil and rock down a slope?

The term that describes the gradual movement of soil and rock down a slope is "creeping." This process is typically very slow and can occur over long periods of time, often resulting from factors like gravity, changes in moisture levels, or freeze-thaw cycles. Creeping is characterized by the continuous and subtle displacement of materials, leading to significant landscape changes even though the movement is almost imperceptible on a day-to-day basis.

Other terms like sliding and flowing refer to more rapid forms of movement. Sliding generally implies a more abrupt and often larger-scale shift of materials along a defined surface or slope, while flowing suggests a movement that is more akin to liquefaction or a cohesive mass that moves in a fluid-like manner. Shifting is a less commonly used term in this specific context and does not convey the measured and gradual nature associated with true creeping motion.