nonachiever vs underperformer

nonachiever and underperformer both are nouns.

Word	Noun	Adjective	Verb	Adverb
nonachiever	Yes	No	No	No
underperformer	Yes	No	No	No

As nouns, nonachiever and underperformer are synonyms defined as:

nonachiever and underperformer: a student who does not perform as well as expected or as well as the IQ indicates

Other synonyms of nonachiever include underachiever.

nonachiever (noun)	underperformer (noun)
a student who does not perform as well as expected or as well as the IQ indicates	a business that is less successful than expected
	a student who does not perform as well as expected or as well as the IQ indicates