sludge

Everyday

1. Thick, soft, wet mud or a mix of mud and dirty liquid. tree →
2. Thick, dirty stuff left after cleaning water or from machines: sewage sludge, oil sludge. tree →
3. (informal) Any thick, unpleasant mess, like soggy food or slushy snow. tree →
4. A sludge-hammer is a big, heavy hammer. tree →

In the lessons

In everyday life, sludge collects at the bottom of ponds, gutters and drains. In science and geography, water treatment plants separate sludge from water, and some sludge becomes fertiliser or energy. In stories, sludge gives a gross, squelchy feel. Phrases: green sludge, a layer of sludge, sewage sludge.

Examples

• Our wellies sank into the sludge. tree →
• Green sludge covered the bottom of the pond. tree →
• The drain was blocked with sludge. tree →
• At the water works, sludge is taken out of the dirty water. tree →
• The porridge turned into a cold grey sludge. tree →
• Car engines can fill with oil sludge if they are not serviced. tree →
• Ole Brer Fox, he grab de sludge-hammer, he did, en he come down on de rock--blim! tree →

Note

Uncountable: "some sludge", "a layer of sludge". Adjective: sludgy. Similar: slime, mud, gunge (UK), goo, slush (melting snow).