Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun scum

2 senses of scum

Sense 1
trash, scum -- (worthless people)
       => rabble, riffraff, ragtag, ragtag and bobtail -- (disparaging terms for the common people)

Sense 2
scum -- (a film of impurities or vegetation that can form on the surface of a liquid)
       => film -- (a thin coating or layer; "the table was covered with a film of dust")

Synonyms/Hypernyms (Ordered by Estimated Frequency) of verb scum

1 sense of scum

Sense 1
scum -- (remove the scum from)
       => get rid of, remove -- (dispose of; "Get rid of these old shoes!"; "The company got rid of all the dead wood")