criminal vs illegal

criminal is a noun but illegal is not a noun.

Word	Noun	Adjective	Verb	Adverb
criminal	Yes	Yes	No	No
illegal	No	Yes	No	No

criminal (noun)	illegal (noun)
someone who has committed a crime or has been legally convicted of a crime

criminal (adjective)	illegal (adjective)
guilty of crime or serious offense	prohibited by law or by official or accepted rules
involving or being or having the nature of a crime
bringing or deserving severe rebuke or censure