[{"Bold_text": "noun", "List Items": ["a film or layer of foul or extraneous matter that forms on the surface of a liquid.", "refuse or offscourings.", "a low, worthless, or evil person.", "such persons collectively; riffraff; dregs.", "scoria(def1) scoria(def1)."]}, {"Bold_text": "verb (used with object)", "List Items": ["to remove the scum from.", "to remove as scum."]}, {"Bold_text": "verb (used without object)", "List Items": ["to form scum; become covered with scum."]}]