- 1[uncountable, singular] a layer of bubbles or an unpleasant substance that forms on the surface of a liquid Skim off any scum. stinking water covered by a thick green scum
- 2(informal) [plural] an insulting word for people that you strongly disapprove of Don't waste your sympathy on scum like that. Drug dealers are the scum of the earth (= the worst people there are).
NAmE//ˈskʌmi//
adjective scummy water scummy people dropping litterSee scum in the Oxford Advanced Learner's DictionaryCheck pronunciation: scum