silt
n.
mid-15c., originally "sediment deposited by seawater," probably from a Scandinavian source (compare Norwegian and Danish sylt "salt marsh"), or from Middle Low German or Middle Dutch silte, sulte "salt marsh, brine," from Proto-Germanic *sultjo- (cognates: Old English sealt, Old High German sulza "saltwater," German Sulze "brine"), from PIE *sal- (see salt, n.).
v.
"to become choked with silt" (of river channels, harbors, etc.), 1799, from silt, n.. Related: Silted; silting.