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)

silts, present (3rd person singular) silted, past participle, past silting present participle

1. to become filled or choked up with silt.

verb (used with object)

silts, present (3rd person singular) silted, past participle, past silting present participle

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

Derived Forms

• siltation
  noun
• silty
  adjective

Inflected Forms

Participles

• silting
  present
• silted
  past

Conjugated Forms

Present

• silt
  simple
• silts
  simple
• have silted
  perfect
• has silted
  perfect
• am silting
  progressive
• are silting
  progressive
• is silting
  progressive
• have been silting
  perfect progressive
• has been silting
  perfect progressive

Past

• silted
  simple
• had silted
  perfect
• was silting
  progressive
• were silting
  progressive
• had been silting
  perfect progressive

Future

• will silt
  simple
• will have silted
  perfect
• will be silting
  progressive
• will have been silting
  perfect progressive

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

He fears the project will silt up the creek and Flathead Lake and destroy fish and habitat.

From The Wall Street Journal • Jul. 5, 2026

The Hansen Dam Aquatic Center pool was constructed in 1999 in a $15-million project to replace a previous pool in the area that was filled with silt.

From Los Angeles Times • Jun. 11, 2026

Removing silt from these spots would increase the overall flow rate through the delta, allowing even more water retention in reservoirs.

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

But the trash wedged itself under his armpits and the balls of his feet, as if it wanted to be useful one last time before sinking into the silt at the bottom.

From "A Wish in the Dark" by Christina Soontornvat

Related Words

• residue
• sand