1. A film of impurities or vegetation that can form on the surface of a liquid
   "A layer of green scum covered the stagnant pond"
    
2. [informal] Worthless people
   "The politician referred to his opponents as scum, causing outrage";
   - trash [N. Amer, informal]

1. Remove the scum from
   "The cook scummed the broth before serving"

Derived forms: scums, scumming, scummed

Type of: film, get rid of, rabble, ragtag, ragtag and bobtail, remove, riffraff

Encyclopedia: Scum