vicious vs criminal

vicious is not a noun while criminal is a noun.

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

As adjectives, vicious and criminal are synonyms defined as:

Other synonyms of vicious include condemnable, deplorable, reprehensible.

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

vicious (adjective)	criminal (adjective)
(of persons or their actions) able or disposed to inflict pain or suffering	guilty of crime or serious offense
marked by deep ill will; deliberately harmful	involving or being or having the nature of a crime
having the nature of vice	bringing or deserving severe rebuke or censure
bringing or deserving severe rebuke or censure