scum

nouns

worthless people
scum, trash
a film of impurities or vegetation that can form on the surface of a liquid
scum
is derived from
scummy
is a type of (narrower)
a thin coating or layer
"the table was covered with a film of dust"
film

verbs

remove the scum from
scum
is a type of (narrower)
dispose of
"Get rid of these old shoes!"; "The company got rid of all the dead wood"
get rid of, remove