scum

Everyday

1. A dirty layer that forms on top of a liquid, like on a pond or bath water. tree →
2. An insulting word for people thought to be very bad. tree →

In the lessons

In science and everyday life, scum forms on a pond, on boiling water when cooking, or around the bath (soap scum). Pupils may notice scum in experiments when making things like soap. Phrases: soap scum, pond scum, skim off the scum.

Examples

• There was green scum on the pond. tree →
• Skim the scum off the soup. tree →
• Soap scum makes the bath look dirty. tree →
• The scum floated on top of the water. tree →
• We cleaned the scum from the fish tank. tree →
• Do not drink water with scum on it. tree →
• I take them when they come in my way, but I do not hunt the Bandar-log, or frogs--or green scum on a water-hole, for that matter.” tree →

Note

Uncountable: "some scum", not "a scum". Using "scum" about people is very rude; do not call people that. Safety: scum on a pond can mean the water is dirty or has harmful algae; keep pets and children out.