\ ˈsləj How to pronounce sludge (audio) \

Definition of sludge

1 : mud, mire especially : a muddy deposit (as on a riverbed) : ooze
2 : a muddy or slushy mass, deposit, or sediment: such as
a : precipitated solid matter produced by water and sewage treatment processes
b : muddy sediment in a steam boiler
c : a precipitate or settling (such as a mixture of impurities and acid) from a mineral oil

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Other Words from sludge

sludgy \ ˈslə-​jē How to pronounce sludgy (audio) \ adjective

Synonyms for sludge


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Examples of sludge in a Sentence

after a day of heavy rain, the fairgrounds had turned into pure sludge I can't bring myself to read that sludge.
Recent Examples on the Web Often the act is built on a psychic landfill of toxic sludge. Kyle Smith, National Review, "Judd Apatow’s Comedy Masterpiece," 1 May 2020 Then it is strained through a sieve to filter out all the sludge-like solids, followed by filtering. Jennifer Ouellette, Ars Technica, "The chemistry of cold-brew coffee is so hot right now," 9 Apr. 2020 The company handles municipal sludge hauling, grease trap, grit trap, septic tank, lift station and lint trap cleaning and maintenance. Katherine Feser, Houston Chronicle, "Company offers wastewater discounts to restaurants," 8 Apr. 2020 At House Street in Belmont, many residential wells were polluted by PFAS emanating from historical landfills used by Wolverine to dispose of its PFAS-laden sludges. Keith Matheny, Detroit Free Press, "State, townships near $69.5M settlement with Wolverine shoe maker over PFAS contamination," 10 Dec. 2019 Brent Walls, the Upper Potomac Riverkeeper, and Maryland environmental regulators have documented pools of black sludge smelling of rotten eggs, believed to be black liquor mixed with coal ash, the group said. Scott Dance,, "Environmentalists: Shuttered Luke paper mill is leaking black liquor, a controversial renewable energy source," 19 Nov. 2019 These pools of super-salty sludge can even host strange bacteria on the bottom of the sea floor—bacteria that scientists suspect could be found in other parts of the solar system. Jennifer Leman, Popular Mechanics, "So...Why Is the Ocean So Salty?," 17 Oct. 2019 The plant could also burn sludge from Anchorage Water & Wastewater Utility, eliminating the need for a new $100 million incinerator for the utility, Spafford said. USA TODAY, "Rosa Parks statue, newborn polar bear cub, quake rocks Oregon: News from around our 50 states," 2 Dec. 2019 Six pipe breaks in December left rivers tainted, streets full of sludge, and even some homes barely habitable from the smell alone. Tim Pearce, Washington Examiner, "Florida mayor pleads for help after city swamped in 211M gallons of sewage," 18 Feb. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'sludge.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of sludge

15th century, in the meaning defined at sense 1

History and Etymology for sludge

Middle English slugge, perhaps alteration of slicche mud, slush; akin to Old High German slīh mire

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Time Traveler for sludge

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The first known use of sludge was in the 15th century

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Statistics for sludge

Last Updated

12 May 2020

Cite this Entry

“Sludge.” Dictionary, Merriam-Webster, Accessed 29 May. 2020.

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More Definitions for sludge


How to pronounce sludge (audio)

English Language Learners Definition of sludge

: thick, soft, wet mud
: a soft, thick material that is produced in various industrial processes (such as in the treatment of sewage)
: a thick material that can form in the oil in an engine and cause engine problems


\ ˈsləj How to pronounce sludge (audio) \

Kids Definition of sludge

: a soft muddy mass resulting from sewage treatment


\ ˈsləj How to pronounce sludge (audio) \

Medical Definition of sludge

 (Entry 1 of 2)

: a semisolid precipitated mass or deposit biliary sludge especially : sludged blood
sludged; sludging

Medical Definition of sludge (Entry 2 of 2)

: to form sludge positions that cause blood to sludge— L. K. Altman

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More from Merriam-Webster on sludge

Thesaurus: All synonyms and antonyms for sludge

Rhyming Dictionary: Words that rhyme with sludge

Spanish Central: Translation of sludge

Nglish: Translation of sludge for Spanish Speakers

Britannica English: Translation of sludge for Arabic Speakers

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