1. (a.) Guilty of crime or sin.

2. (a.) Involving a crime; of the nature of a crime; -- said of an act or of conduct; as, criminal carelessness.

3. (a.) Relating to crime; -- opposed to civil; as, the criminal code.

4. (n.) One who has committed a crime; especially, one who is found guilty by verdict, confession, or proof; a malefactor; a felon.

Judas Mafioso aberrant abnormal abominable actionable against the law amoral anarchic anarchistic anomic arraignable arrant at fault atrocious bad bad guy bad person base betrayer black black-market blackguard blamable blameworthy bootleg censurable chargeable conscienceless contraband contrary to law convict corrupt corrupted crook crooked culpable culprit damnable dark deceiver delinquent depraved desperado desperate criminal deviant devious disgraceful dishonest dishonorable double-dealer doubtful dubious evasive evil evildoer evildoing execrable faulty felon felonious fishy flagitious flagrant flawed foul fraudulent fugitive gallows bird gangster gaolbird guilty hardly the thing heinous hood hoodlum hooligan ignominious ill-got ill-gotten illegal illegitimate illicit immoral impeachable impermissible implicated improper inappropriate incorrect inculpated indecorous indictable indirect infamous iniquitous insidious involved irregular jailbird justiciable knave knavish lawbreaker lawless low malefactor malefactory malevolent malfeasant malfeasor miscreant misfeasor mobster monstrous naughty nefarious nonconstitutional nonlegal nonlicit not done not kosher not the thing off-base off-color offender out-of-line outlaw outlawed peccant public enemy punishable questionable quisling racketeer rank reprehensible reproachable reprobate reprovable rotten roughneck ruffian sacrilegious scandalous scofflaw scoundrel shady shameful shameless shifty sinful sinister sinner slippery suspicious swindler terrible terrorist thief thug to blame tough traitor transgressor trespasser triable tricky two-timer unallowed unauthorized unconscienced unconscientious unconscionable unconstitutional under-the-counter under-the-table underhand underhanded undue unethical unfit unfitting unforgivable unlawful unofficial unpardonable unprincipled unrighteous unsavory unscrupulous unseemly unspeakable unstatutory unstraightforward unsuitable unwarrantable unwarranted unworthy vicious vile villain villainous wicked without remorse without shame worker of ill wrong wrongdoer wrongdoing wrongful