Definitions

1. noun

the lowest or most vile part of a group or society

“The scum of the city’s underworld was finally caught by the police.”

2. noun

a mass of foam or bubbles forming on the surface of a liquid, especially when it is boiling or fermenting

“The scum that formed on top of the beer was disturbing to drink.”

3. verb

to remove or clear something, especially by scraping it off

“The farmer had to scum the bottom of the old tank to get it ready for use.”

4. verb

to remove scum from (a surface)

“She had to scum the saucepan to get rid of the stubborn stain.”