scum
scum
/skʌm/
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 uncountable, plural (informal, offensive) an offensive word for people who you think are very bad Don't waste your sympathy on scum like that.
Drug dealers are the scum of the earth (= the worst people there are).
Word Origin
Middle English: from Middle Low German, Middle Dutch schūm, of Germanic origin.
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