good-for-naught vs idler

good-for-naught and idler both are nouns.

Word	Noun	Adjective	Verb	Adverb
good-for-naught	Yes	Yes	No	No
idler	Yes	No	No	No

As nouns, idler is a hypernym of good-for-naught; that is, idler is a word with a broader meaning than good-for-naught:

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

good-for-naught (noun)	idler (noun)
an idle worthless person	person who does no work

good-for-naught (adjective)	idler (adjective)
without merit; of little or no value or use