What is the name of sediment that is deposited by moving water?

The term that specifically refers to sediment deposited by moving water is "alluvium." Alluvium generally describes sediment transported by rivers and streams, encompassing a variety of particle sizes, from fine silt to larger gravel. This sediment accumulates in floodplains, riverbeds, and deltas, playing a significant role in shaping landscapes and supporting ecosystems.

Fluvial sediment is a broader category that can refer to any sediment transported by river processes, but alluvium is more specific and widely used in geological contexts to refer directly to the sediment itself. Colluvium refers to material that is moved down slopes primarily due to gravity, often found at the base of hills or slopes, while loess is a wind-blown sediment consisting mainly of silt-sized particles. Alluvium is particularly important in understanding sedimentary processes and river dynamics.