ETYM Latin, neut. of alluvius. Related to Alluvious.
Deposits of earth, sand, gravel, and other transported matter, made by rivers, floods, or other causes, upon land not permanently submerged beneath the waters of lakes or seas.
Matter deposited by river or flood.
Fine silty material deposited by a river. It is deposited along the river channel where the water's velocity is low—for example, on the inside bend of a meander. A flood plain is composed of alluvium periodically deposited by floodwater.