sludge

[ sluhj ]

noun

1. mud, mire, or ooze; slush.
2. a deposit of ooze at the bottom of a body of water.
3. any of various more or less mudlike deposits or mixtures.
4. the sediment in a steam boiler or water tank.
5. broken ice, as on the sea.
6. a mixture of some finely powdered substance and water.
7. sediment deposited during the treatment of sewage.
8. Also called activated sludge. Bacteriology. sewage sediment that contains a heavy growth of microorganisms, resulting from vigorous aeration.
9. a fine, mudlike powder produced by a mining drill.

sludge

/ slʌdʒ /

noun

1. soft mud, snow, etc
2. any deposit or sediment
3. a surface layer of ice that has a slushy appearance
4. (in sewage disposal) the solid constituents of sewage that precipitate during treatment and are removed for subsequent purification

Other Words From

• de-sludge verb (used with object) desludged desludging

Word History and Origins

Origin of sludge¹

First recorded in 1640–50; variant of dialectal slutch, slitch, Middle English slich “slime, wet mud” (compare its derivative slucched “muddy”); apparently of expressive origin

Word History and Origins

Origin of sludge¹

C17: probably related to slush

Example Sentences

For nearly a decade, we have been witnessing all of his bad traits worsening and degrading into a tainted, bitter sludge.

From Salon

Its glacial pace, often accompanied by a viscous sludge it leaves behind, make it a messy if inoffensive kind of pest.

From Los Angeles Times

The sludge swept through communities, destroying hundreds of people’s homes and poisoning the river.

From BBC

When she was in middle school, Alaina Wood learned about an environmental disaster — a coal ash spill into the Emory River, west of Knoxville, Tenn., that released toxic sludge containing arsenic and mercury.

From Los Angeles Times

That oil reached the shores of several nearby fishing villages, coating beaches in black sludge.

From BBC

Related Words

• goo
• grease
• gunk
• muck
• sediment
• silt
• slime