alluvion in WordNet English dictionary

1. clay or silt or gravel carried by rushing streams and deposited where the stream slows down
   alluvial sediment  alluvial deposit  alluvium  alluvion 
   
2. the rising of a body of water and its overflowing onto normally dry land
   "plains fertilized by annual inundations"
   flood  inundation  deluge  alluvion 
   
3. gradual formation of new land, by recession of the sea or deposit of sediment
   alluvion