good-for-nothing vs bum

good-for-nothing and bum both are nouns.

Word	Noun	Adjective	Verb	Adverb
good-for-nothing	Yes	Yes	No	No
bum	Yes	Yes	Yes	No

As nouns, bum is a hypernym of good-for-nothing; that is, bum is a word with a broader meaning than good-for-nothing:

Other hypernyms of good-for-nothing include do-nothing, idler, layabout, loafer.

good-for-nothing (noun)	bum (noun)
an idle worthless person	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

good-for-nothing (adjective)	bum (adjective)
without merit; of little or no value or use	of very poor quality; flimsy

good-for-nothing (verb)	bum (verb)
	ask for and get free; be a parasite
	be lazy or idle