acrimonious, agonizing, atrocious, barbarous, blood-thirsty, brutal, cold, cold-blooded, cold-hearted, crudelis, demoniacal, devilish, diabolical, distressing, evil-minded, ferocious, fiendish, fierce, hard, hardhearted, harsh, heartless, hellish, ill-intentioned, ill-natured, ill-willed, implacable, indifferent to suffering, inhuman, inhumane, insensitive, malevolent, malicious, malign, malignant, merciless, oppressive, painful, pitiless, punishing, relentless, remorseless, ruthless, sadistic, satanic, savage, severe, spiteful, tortuous, treacherous, tyrannical, unbenevolent, uncompassionate, unfeeling, unkind, unmerciful, unnatural, unpitying, unrelenting, unsympathetic, unsympathizing, vicious
associated concepts: cruel and abusive treatment, cruel and barbarous treatment, cruel and inhuman punishment, cruel and inhuman treatment, cruel and unusual punishment, cruel disposition, cruel treatment
bad (offensive), brutal, caustic, cold-blooded, diabolic, harmful, harsh, inexcusable, malevolent, malicious, malignant, oppressive, outrageous, pernicious, relentless, remorseless, ruthless, scathing, severe, sinister, unrelenting, vicious
Burton's Legal Thesaurus. William C. Burton. 2006
adj.Callously causing pain or suffering.n.cruelty
The Essential Law Dictionary. — Sphinx Publishing, An imprint of Sourcebooks, Inc. Amy Hackney Blackwell. 2008.