Merriam-Webster Logo
SINCE 1828
dictionary thesaurus view recents

sludge

noun
Save Word
\ 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
3 : slush sense 5
Other Words from sludge Synonyms Example Sentences Learn More about sludge

Keep scrolling for more

Other Words from sludge

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

Synonyms for sludge

Synonyms

Visit the Thesaurus for More 

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 Then there are the recent oil pipeline spills in the Gulf of Mexico and elsewhere, as well as rollbacks that have permitted the reintroduction of coal sludge into streams and rivers. — Chuck Yarborough, cleveland, "True-life legal thriller ‘Dark Waters’ serves as a warning similar shoals may lie ahead," 2 Dec. 2019 The site also has about 21 tanker rail cars containing phosphorus sludge the company buried rather than clean up, court documents say. — Washington Post, "Court: Company must pay for toxic waste on Idaho tribal land," 19 Nov. 2019 Salles said more than 100 tons of oil sludge has already been collected. — Alessandra Castelli And Tara John, CNN, "Mysterious Brazilian oil spill could be 'criminal,' Bolsonaro says," 9 Oct. 2019 Cosmopolitanism — the idea of moral community among human beings, regardless of social and political affiliation — is alive and well, in spite of whatever iniquitous sludge might ooze out from 1600 Pennsylvania Ave. — Los Angeles Times, "The 11 best art exhibitions to see in L.A. this fall," 12 Sep. 2019 Blood is a surprisingly complicated fluid, in part because the red blood cells in human blood can form long chains, giving it the consistency of sludge. — Jennifer Ouellette, Ars Technica, "Physicists now have even better models for blood spatter from gunshot wounds," 29 Aug. 2019 Right now this brain is brimming with a thick, sugar-and-darkness induced sludge. — Alli Harvey, Anchorage Daily News, "Hello darkness, my old friend. I will play outside to survive you.," 21 Dec. 2019 In 2000, in Martin County, just miles south of Inez, some 306 million gallons of coal sludge oozed down 100 miles of waterways. — Will Meyer, Longreads, "A Green New Jail," 24 Oct. 2019 An order issued earlier this year sets deadlines for fixing sludge processing and nitrogen removal systems that malfunctioned earlier. — Christine Woodside, courant.com, "Dead fish, condoms, brown foam: Sewage has chokehold on Bridgeport’s Black Rock Harbor," 4 Oct. 2019

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.

See More

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

Keep scrolling for more

Learn More about sludge

Time Traveler for sludge

Time Traveler

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

See more words from the same century

Statistics for sludge

Last Updated

4 Feb 2020

Cite this Entry

“Sludge.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/sludge. Accessed 17 Feb. 2020.

Keep scrolling for more

More Definitions for sludge

sludge

noun
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

See the full definition for sludge in the English Language Learners Dictionary

sludge

noun
\ ˈsləj How to pronounce sludge (audio) \

Kids Definition of sludge

: a soft muddy mass resulting from sewage treatment

sludge

noun
\ 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

sludge

intransitive verb
sludged; sludging

Medical Definition of sludge (Entry 2 of 2)

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

Keep scrolling for more

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

Comments on sludge

What made you want to look up sludge? Please tell us where you read or heard it (including the quote, if possible).

Show Comments  Hide Comments 

WORD OF THE DAY

probity

Listen to the pronounciation of probity

See Definitions and Examples »

Get Word of the Day daily email!

Test Your Vocabulary

More Confusing Words—Quiz

  • cats on impossible timber
  • The magician ______ moved the selected card to the top of the deck.
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Add Diction

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ
Love words? Need even more definitions?

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

Words at Play
Ask the Editors
Word Games