scum vs trash

scum and trash both are nouns.

Word	Noun	Adjective	Verb	Adverb
scum	Yes	No	Yes	No
trash	Yes	No	Yes	No

As nouns, scum and trash are synonyms defined as:

scum (noun)	trash (noun)
a film of impurities or vegetation that can form on the surface of a liquid	an amphetamine derivative (trade name Methedrine) used in the form of a crystalline hydrochloride; used as a stimulant to the nervous system and as an appetite suppressant
worthless people	nonsensical talk or writing
	worthless people
	worthless material that is to be disposed of

scum (verb)	trash (verb)
remove the scum from	express a totally negative opinion of
	dispose of (something useless or old)