al·lu·vi·on /əˈluviən/
  沙洲,沖積地,沖積地
  Al·lu·vi·on 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. Law An accession of land gradually washed to the shore or bank by the flowing of water. See Accretion.
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  alluvion
       n 1: gradual formation of new land, by recession of the sea or
            deposit of sediment
       2: the rising of a body of water and its overflowing onto
          normally dry land; "plains fertilized by annual
          inundations" [syn: flood, inundation, deluge]
       3: clay or silt or gravel carried by rushing streams and
          deposited where the stream slows down [syn: alluvial
          sediment, alluvial deposit, alluvium]