The Oxford Thesaurus An A-Z Dictionary of Synonyms - siltn.

1) deposit, sediment, alluvium, ooze, sludge: The irrigation pumps get clogged up with silt. --v. 2) Usually, silt up or over. become clogged or choked or obstructed or dammed or congested: The channel silts up and has to be dredged yearly so that the boats can pass through.