silt

American  

[silt] / sɪlt /

noun

1. earthy matter, fine sand, or the like carried by moving or running water and deposited as a sediment.

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verb (used without object)

1. to become filled or choked up with silt.

verb (used with object)

1. to fill or choke up with silt.

silt British  

/ sɪlt /

noun

1. a fine deposit of mud, clay, etc, esp one in a river or lake

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verb

1. (usually foll by up) to fill or become filled with silt; choke

silt Scientific  

/ sĭlt /

1. A sedimentary material consisting of grains or particles of disintegrated rock, smaller than sand and larger than clay. The diameter of the particles ranges from 0.0039 to 0.0625 mm. Silt is often found at the bottom of bodies of water where it accumulates slowly by settling through the water.

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Other Word Forms

• desilt
  verb (used with object)
• siltation
  noun
• silty
  adjective

Etymology

Origin of silt

1400–50; late Middle English cylte gravel, perhaps originally salty deposit; compare Old English unsylt unsalted, unseasoned, sylting seasoning, syltan to salt, season, Norwegian sylt salty swamp, German Sülze salt marsh, brine

Explanation

Silt is the fine bits of clay and sand that become sediment settling at the bottom of a river or lake. If there's a lot of silt flowing in a river, it looks murky. Silt is the super-fine dirt that you might see at the bottom of a lake or river. When your feet touch silt it feels slimy, and once it’s stirred it up the water looks muddy. Where the Mississippi River enters the Gulf of Mexico, a lot of silt has been deposited and over time has built up a portion of land called the Mississippi Delta. The region surrounding this accumulation of silt is home to music called the Delta Blues.

Example Sentences

In a practice that ought to inspire progressives, those farmers deepened the delta channels and spread over their surrounding farmland the rich silt they excavated or used it to reinforce the levees.

From The Wall Street Journal • Apr. 17, 2026

The bee began digging into the fine clay-rich silt that had built up in the darker parts of the cave.

From Science Daily • Apr. 3, 2026

However, it could now flush silt from its reservoirs without prior warning - potentially causing damage downstream in Pakistan.

From BBC • Apr. 25, 2025

I wanted to show her what I learned: that we are never alone among the tadpoles, silt and stones, that we belong to nature too.

From Los Angeles Times • Feb. 28, 2025

“Groundbreaking began August 1966. The tall towers needed a strong foundation. Workers had to dig deep through silt to find firm soil.”

From "Towers Falling" by Jewell Parker Rhodes

Related Words

• residue
• sand