meritless vs good-for-nothing

meritless is not a noun while good-for-nothing is a noun.

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

As adjectives, meritless and good-for-nothing are synonyms defined as:

meritless and good-for-nothing: without merit; of little or no value or use

Other synonyms of meritless include good-for-naught, no-account, no-count, no-good, sorry.

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

meritless (adjective)	good-for-nothing (adjective)
without merit; of little or no value or use	without merit; of little or no value or use