Sludge/slʌdʒ/nounSolids separated from suspension in a liquid.A residual semi-solid material left from industrial, water treatment, or wastewater treatment processes.A sediment of accumulated minerals in a steam boiler.Synonyms: mire, mud, ooze, slushverbTo slump or slouch.To slop or drip slowly.🔗 Explore synonyms & relationships🌍 See word origin & history