sludge

noun

ˈsləj 

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 

adjective

Synonyms

• guck
• gook
• mire
• muck
• mud
• ooze
• slime
• slop
• slush

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

However, trade classification is not the only contributor to trade sludge. —Steve Banker, Forbes.com, 11 Apr. 2025

Pacific Palisades experienced a major intersection submerged in three feet of sludge, and roads near the Eaton Fire burn scar were overtaken by several feet of mud, trees, and vegetation. —David Faris, MSNBC Newsweek, 11 Apr. 2025

Hazel can pull, push, and even infiltrate the minds of the opposing spirits using her abilities, dodging and diving to avoid rogue slashes or a demonic helping of sludge. —Sarah Thwaites, Rolling Stone, 3 Apr. 2025

In the 1980s, the Environmental Protection Agency cited the GSD for the pumping of toxic sludge laced with PCBs into a small lagoon in violation of the Clean Water Act. —Carole Carlson, Chicago Tribune, 22 Mar. 2025

Word History

Etymology

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

First Known Use

15th century, in the meaning defined at sense 1

Rhymes for sludge

• budge
• drudge
• frage
• fudge
• grudge
• judge
• mudge
• nudge
• rudge
• smudge
• trudge
• adjudge

Kids Definition

sludge

noun

ˈsləj 

1

: mud, mire

2

: a muddy or slushy mass

especially : solid matter produced by water and sewage treatment processes

sludgy

ˈsləj-ē 

adjective

Medical Definition

sludge

1 of 2 noun

ˈsləj 

: 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