As I'm sure you could guess from looking, that today's word, maledicent, has something to do with being bad, like maleficent, malefactor, malpractice, etc... In fact, it means "one who is addicted to abusive speech." I can't really think of any good examples of this kind of person in real life. Some characters from "A Bit of Fry & Laurie" sketches come to mind...
As for the prefix mal, it means "bad, badly or ill," coming from Old French mal, from the Latin adverb male, from malus, meaning "bad."
The Lonely Alchemist