ALLUVIUM

Noun

alluvium (plural alluviums or alluvia)

soil, clay, silt or gravel deposited by flowing water, as it slows, in a river bed, delta, estuary or flood plain

Synonyms: alluvion, alluvial deposit

Source: Wiktionary

Al*lu"vi*um, n.; pl. E. Alluviums, L. Alluvia. Etym: [L., neut. of alluvius. See Alluvious.] (Geol.)

Definition: 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. Lyell.

Source: Webster’s Unabridged Dictionary 1913 Edition