Alluvion

Al·lu·vi·on

Alluvion

n.
  1. Wash or flow of water against the shore or bank.
  2. An overflowing; an inundation; a flood.
  3. Matter deposited by an inundation or the action of flowing water; alluvium.
    The golden alluvions are there [in California and Australia] spread over a far wider space: they are found not only on the banks of rivers, and in their beds, but are scattered over the surface of vast plains.
    — R. Cobden.
  4. An accession of land gradually washed to the shore or bank by the flowing of water. See Accretion. (Law)