flagitious in WordNet English dictionary

1. shockingly brutal or cruel
   "murder is an atrocious crime"; "a grievous offense against morality"; "a grievous crime"; "no excess was too monstrous for them to commit"
   atrocious  flagitious  grievous  monstrous 
   
2. extremely wicked, deeply criminal
   "a flagitious crime"; "heinous accusations"
   flagitious  heinous