1 of 2


: loose sedimentary material with rock particles usually ¹/₂₀ millimeter or less in diameter
also : soil containing 80 percent or more of such silt and less than 12 percent of clay
: a deposit of sediment (as by a river)
silty adjective


2 of 2


silted; silting; silts

intransitive verb

: to become choked or obstructed with silt
often used with up
the channel silted up

transitive verb

: to choke, fill, cover, or obstruct with silt or mud
siltation noun

Examples of silt in a Sentence

Verb The entrance to the creek had silted shut.
Recent Examples on the Web
Today, the underwater stilts are mostly buried under silt. Sarah Kuta, Smithsonian Magazine, 24 Aug. 2023 Colleen Dooley, a retired teacher, returned to her condominium complex in Ludlow to find the grounds covered in silt and mud and the pool filled with muddy river water. Lisa Rathke, Anchorage Daily News, 12 July 2023 Experts think the fishing boat sank unexpectedly and was covered in silt over time, inadvertently preserving it. Meilan Solly, Smithsonian Magazine, 26 Dec. 2023 Families fleeing the flood zone crawled through traffic in cars caked in red silt; dozens of aid trucks and excavators headed in the opposite direction. Kareem Fahim, Washington Post, 14 Sep. 2023 Thirty-foot tides, glacial silt and iron-eating microbes were top of mind for U.S. Transportation Secretary Pete Buttigieg after his visit to the Port of Alaska in Anchorage on Tuesday. Iris Samuels, Anchorage Daily News, 16 Aug. 2023 Archaeologists dated the White Sands footprints thanks to grass seeds trapped in the layers of clay and silt above and below the tracks, which helped bracket their possible age. Kiona N. Smith, Ars Technica, 10 July 2023 Some layers were fine, like silt, others contained small rocks, and some had larger stones, perhaps carried by intense flood events. Ernie Cowan, San Diego Union-Tribune, 7 Jan. 2024 Excavation of the grave took place beside a river on a floodplain, and it’s thought that a layer of silt must have quickly covered the site, creating conditions for the bronze objects to remain remarkably well-preserved. Sean Mowbray, Discover Magazine, 28 Dec. 2023
All the while, the Guadalquivir River, which allowed ships into Seville, began to silt up, forcing trade southward to the coastal town of Cádiz. Walker Mimms, New York Times, 12 Jan. 2023 Cathedral-like sandstone canyons were resurrected, and sunlight reached the silt-clogged floors for the first time in generations. Abrahm Lustgarten, ProPublica, 22 Dec. 2022 Throws that made octo-contact were also more likely to be accomplished with a specific set of arms, and the projectile was more likely to be silt. Emma Marris, Scientific American, 10 Nov. 2022 Faison finishes shaking; pale flecks of shell and silt float around him. Emily Cataneo, Smithsonian Magazine, 12 Aug. 2022 Climate change damages the streams where they are hatched, and not just by raising the water temperature: Droughts alter stream flow, forest fires destroy shoreline habitat, and mudslides silt up rivers. Joshua Partlow, Anchorage Daily News, 29 Mar. 2022 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'silt.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History



Middle English cylte, probably of Scandinavian origin; akin to Norwegian dialect sylt beach flooded at high tide; akin to Old High German sulza salt marsh, Old English sealt salt

First Known Use


15th century, in the meaning defined at sense 1


1799, in the meaning defined at intransitive sense

Time Traveler
The first known use of silt was in the 15th century

Dictionary Entries Near silt

Cite this Entry

“Silt.” Dictionary, Merriam-Webster, Accessed 21 Feb. 2024.

Kids Definition


1 of 2 noun
: very small particles left as sediment from water
also : a soil made up mostly of silt with little clay
: a deposit of sediment (as by a river)
silty adjective


2 of 2 verb
: to make or become choked, blocked, filled, or covered with silt
the river channel silted up
Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!