scum bag vs bum

scum bag and bum both are nouns.

Word	Noun	Adjective	Verb	Adverb
scum bag	Yes	No	No	No
bum	Yes	Yes	Yes	No

As nouns, scum bag and bum are synonyms defined as:

scum bag and bum: a person who is deemed to be despicable or contemptible

Other synonyms of scum bag include crumb, dirty dog, git, lowlife, puke, rat, rotter, scumbag, skunk, so-and-so, stinker, stinkpot.

scum bag (noun)	bum (noun)
a person who is deemed to be despicable or contemptible	the fleshy part of the human body that you sit on
	a vagrant
	a person who is deemed to be despicable or contemptible
	person who does no work

scum bag (adjective)	bum (adjective)
	of very poor quality; flimsy

scum bag (verb)	bum (verb)
	ask for and get free; be a parasite
	be lazy or idle