scum bag vs crumb

scum bag and crumb both are nouns.

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

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

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

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

scum bag (noun)	crumb (noun)
a person who is deemed to be despicable or contemptible	small piece of e.g. bread or cake
	a person who is deemed to be despicable or contemptible
	a very small quantity of something