the precipitate produced by sewage treatment
"The workers had to pump out thick layers of sludge from the bottom of the city's main wastewater plant after a heavy rainstorm."
Solids separated from suspension in a liquid.
"The emergency physician quickly wrote "SLUDGE" on the patient's chart as an acronym to recall the classic signs of organophosphate poisoning."
An acronym used to help remember the common symptoms of certain affections of a cholinergic toxidrome: "salivation, lacrimation, urination, defecation, gastrointestinal upset, emesis".
To slump or slouch.
"After sitting at his desk all morning, John's shoulders began to sludge forward under the weight of stress."