noun

• (uncountable) Mud or fine earth deposited from running or standing water.
  "A large tube is then followed over several silt banks to surface after a total dive of 200 m in a large passage containing an active streamway – The San Agustin Way. 5 m before the passage surfaces another line junction is passed, ..."
• (uncountable, by extension) Any material with similar physical characteristics, regardless of its origins or transport.
• (countable, geology) A particle from 3.9 to 62.5 microns in diameter, following the Wentworth scale.
  "Above the lower headcut, phreatophytic mesquite and little leaf sumac hug the banks, drawing pendulate water from the silts remaining from former marsh deposits and sending long taproots into channel stores."

verb

• (transitive) To clog or fill with silt.
• (intransitive) To become clogged with silt.
  "Subject to flooding by the six small rivers coming together just west of the city, the main river below the city has long been shallow and subject to silting. The Communists have both maintained the earlier pattern of dredging the river, and have built a bypass flood canal around the city on the south side to relieve flood pressures. Though dredging can keep the river navigable for small ships, a new artificial port, Sinkang, able to take 10,000 ton ships at all times, was created at T'ang-ku. This is kept open for about two months during winter by icebreakers."
• (ambitransitive) To flow through crevices; to percolate.