- Sludge is a substance that is between solid and liquid form.
- An example of sludge is a mass of mud formed in a river bed after a flood.
- An example of sludge is the treated material from a sewage plant.
sludge definition by Webster's New World
- mud, mire, or ooze covering the ground or forming a deposit at the bottom of bodies of water
- spongy lumps of drift ice
- any heavy, slimy deposit, sediment, or mass, as the waste resulting from oil refining, the mud brought up by a mining drill, the precipitate in a sewage tank, the sediment in a steam boiler or crankcase, etc.
Origin: variant, variety of slutch, sludge, mud: akin to Middle English sluchched, muddy, probably ultimately ; from Indo-European base an unverified form (s)leu-, to hang limply from source sleet, Middle High German slote, mud, ooze
sludge definition by American Heritage Dictionary
- Semisolid material such as the type precipitated by sewage treatment.
- Mud, mire, or ooze covering the ground or forming a deposit, as on a riverbed.
- Finely broken or half-formed ice on a body of water, especially the sea.
- An agglutination or aggregation of blood cells forming a semisolid mass that often impedes circulation.
Origin: Perhaps alteration of dialectal slutch, mire.
- sludgˈy adjective