n. One who derives pleasure through cruelty or pain to others.
The Century Dictionary and Cyclopedia
n. One who practises sadism.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. someone who obtains pleasure from inflicting pain or others
Word Usage
""Seidl has been described as a sadist, but underneath all the gloom and doom and constant cruelty is obviously a disappointed idealist crying out for people to care for one another.""