ne'er-do-well vs good-for-nothing

ne'er-do-well and good-for-nothing both are nouns.

Word	Noun	Adjective	Verb	Adverb
ne'er-do-well	Yes	No	No	No
good-for-nothing	Yes	Yes	No	No

As nouns, ne'er-do-well and good-for-nothing are synonyms defined as:

Other synonyms of ne'er-do-well include goldbrick, good-for-naught, goof-off, no-account.

ne'er-do-well (noun)	good-for-nothing (noun)
an idle worthless person	an idle worthless person

ne'er-do-well (adjective)	good-for-nothing (adjective)
	without merit; of little or no value or use