Definition of "sludge" [sludge]

• Semisolid material such as the type precipitated by sewage treatment. (noun)
• Mud, mire, or ooze covering the ground or forming a deposit, as on a riverbed. (noun)
• Finely broken or half-formed ice on a body of water, especially the sea. (noun)
• An agglutination or aggregation of blood cells forming a semisolid mass that often impedes circulation. (noun)
• To agglutinate or aggregate into a semisolid mass; form a sludge. Used of blood cells. (verb-intransitive)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "It's pretty funny how Maureen "sludgenurse" Reilly just constantly uses the term sludge over and over, along with all sorts of standard alarmist tactics in "arguing" her point."
• "However, the sludge is then put into Giant Vats where anarobic bacteria (through their metabolism) break down the sludge and forms the methane. this methane is then collected and used to generate power for the Sewage treatment plant."
• "The red sludge is a byproduct of bauxite, a material used in manufacturing aluminum."