silt (n.) Look up silt at Dictionary.com
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.)).
silt (v.) Look up silt at Dictionary.com
"to become choked with silt" (of river channels, harbors, etc.), 1799, from silt (n.). Related: Silted; silting.