'alluvion' definitions:

Gradual formation of new land, by recession of the sea or deposit of sediment

The rising of a body of water and its overflowing onto normally dry land; "plains fertilized by annual inundations" [syn: flood, inundation, deluge, alluvion]

Clay or silt or gravel carried by rushing streams and deposited where the stream slows down [syn: alluvial sediment, alluvial deposit, alluvium, alluvion]