-vēəm noun
( plural alluviums -ēəmz ; or allu·via -ēə)
Etymology: Late Latin, neuter of alluvius alluvial, from Latin alluere
: clay, silt, sand, gravel, or similar detrital material deposited by running water especially during recent geologic time, the deposits ordinarily occurring on the floodplains of streams or as alluvial fans or cones at places where streams issuing from mountains lose velocity and deposit their contained sediment on a valley floor