atrocious, barbaric, barbarous, bestial, bloody, bowelless, brutal, brutish, coldhearted, cruel, cutthroat, dog-eat-dog, feral, ferine, ferocious, fierce, flinty, hard, hardhearted, harsh, heartless, inclement, inexorable, inhuman, inhumane, ironhearted, kill-crazy, malign, malignant, marblehearted, merciless, murderous, noncivilized, relentless, remorseless, ruthless, sanguinary, savage, stony, tameless, uncivilized, uncompassionate, uncompassioned, unfeeling, unforgiving, ungentle, unmerciful, unpitiful, unpitying, unremorseful, unsympathetic, unsympathizing, untamed, unyielding, vicious, wild, without mercy