: one characterized by sadism: a person who takes pleasure in inflicting pain, punishment, or humiliation on others
a sexual sadist
He's a sadist and, where Toby is concerned, an unusually relentless one: he's in the boy's face constantly, prodding, belittling, taunting. Terrence Rafferty
To the penal colony, the cat-o'-nine-tails was a tool more basic than the hoe. On Norfolk Island, where the camp was commanded by a succession of sadists, there were other forms of torture as well … Clive James