sludge

1 of 2

noun

ˈsləj How to pronounce sludge (audio)
Synonyms of sludgenext
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
sludgy
ˈslə-jē How to pronounce sludge (audio)
adjective

sludgy

2 of 2

adjective

-jē How to pronounce sludgy (audio)
-ji
-er/-est
: full of sludge : muddy, slushy

Synonyms of sludge

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Noun

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Examples of sludge in a Sentence

Noun 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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Noun
Inline water filters can be installed and are widely used to trap dirt, debris, and sludge. — Sj McShane, Martha Stewart, 3 July 2026 Every bucket, every rebound, every screen oozed difficulty, as if each player was covered in sludge. — Chris Branch, New York Times, 4 June 2026 After removing the carcasses, spray the surface with a garden hose or pressure washer to remove wings and other insect parts, sludge, and stains. — Karen Brewer Grossman, Southern Living, 29 June 2026 Brine is a super-concentrated, suffocating saltwater sludge, which kills marine life. — Mrigakshi Dixit, Interesting Engineering, 27 May 2026 See All Example Sentences for sludge

Word History

Etymology

Noun

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

First Known Use

Noun

15th century, in the meaning defined at sense 1

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

Rhymes for sludge

See All Rhymes for sludge

Browse Nearby Words

slud
sludge
sludge acid
See all Nearby Words

Cite this Entry

“Sludge.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/sludge. Accessed 7 Jul. 2026.

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Kids Definition

sludge

noun
ˈsləj How to pronounce sludge (audio)
1
: mud, mire
2
: a muddy or slushy mass
especially : solid matter produced by water and sewage treatment processes
sludgy
ˈsləj-ē How to pronounce sludge (audio)
adjective

Medical Definition

sludge

1 of 2 noun
ˈsləj How to pronounce sludge (audio)
: a semisolid precipitated mass or deposit
biliary sludge
especially : sludged blood

sludge

2 of 2 intransitive verb
sludged; sludging
: to form sludge
positions that cause blood to sludge—L. K. Altman

More from Merriam-Webster on sludge

Nglish: Translation of sludge for Spanish Speakers

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