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
• desilt
  verb (used with object)
• 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

See Examples For:

silt silts silted silting

In a day of action at Syston Brook, volunteers mucked in to shovel "absolutely solid" silt out of the concrete-bottomed channel, which was then removed by the Environment Agency.

From BBC ● Aug. 3, 2026

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

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

In many places the grass was flattened, half buried in silt and gravel.

From "Abel's Island" by William Steig

Premier Marinas, which owns Brighton Marina, has said dredging, which involves removing natural silts that settle in the marina basin, is needed to ensure safe navigation for boats.

From BBC ● Aug. 28, 2025

The silts and sand are a "valuable local resource" that contractors and local governments use as fill material in residential and industrial projects, the Army Corps said.

From Scientific American ● Sep. 17, 2019

About 70% of the hull has survived, well-preserved in the Nile silts.

From The Guardian ● Mar. 17, 2019

Scientists warn that any efforts to repair Wular will be futile unless the plan also deals with areas far upstream, where lake-clogging soil and silts are still being loosed from newly deforested lands.

From Seattle Times ● Nov. 11, 2016

But Hess’s readings showed that the ocean floor offered anything but the gooey smoothness of ancient silts.

From "A Short History of Nearly Everything" by Bill Bryson

The system is also 70% silted or clogged after over a century of use, Mr Bonoan told news outlet ABS-CBN News.

From BBC ● Jul. 23, 2025

When the port silted up, Bladensburg, a few miles downriver, was chartered in 1742 as the new port.

From Washington Post ● Jul. 9, 2021

But never have the lakes been silted as they are today,” says Simiyu.

From The Guardian ● Dec. 13, 2020

Malacca’s port, once one of the richest on earth, silted up, and the city became a historical footnote.

From New York Times ● Apr. 11, 2020

A dam across the Missouri River in Nebraska silted up so disastrously that a noisome ooze began to pour into the town of Niobrara, eventually forcing its permanent abandonment.

From "A Walk in the Woods" by Bill Bryson

Geographers had already noticed that rivers tend to avulse at the foot of mountains, where slopes change dramatically and sediment settles out, silting up the bed.

From Science Magazine ● May 13, 2021

Thanks to silting and reclamation in the tidal Liffey, Usher’s Island itself has for centuries been joined to the mainland.

From New York Times ● May 11, 2021

The Chesapeake has struggled for decades from overfishing, silting and pollution, especially from runoff from urban areas and farms.

From Reuters ● Jun. 16, 2014

One mile down the hill, the road crosses the Anacostia River, forever altered by two centuries of silting and an enormous Army Corps of Engineers flood-control project.

From Washington Post ● Jul. 30, 2012

Yes, everything was once water, but the Earth formed out of the oceans by a natural process—similar, he thought, to the silting he had observed at the delta of the Nile.

From "Cosmos" by Carl Sagan

Related Words

• residue
• sand