atrocious, barbarian, barbaric, barbarous, bestial, bloody, bowelless, brutal, brutish, callous, cold, crude, cruel, cutthroat, dog-eat-dog, feral, ferine, ferocious, fierce, hard, harsh, heartless, illiberal, implacable, inclement, inconsiderate, indifferent, inexorable, inflexible, inhuman, inhumane, insensitive, kill-crazy, malevolent, malign, malignant, mortal, murderous, noncivilized, pitiless, relentless, remorseless, rough, rude, ruthless, sanguinary, savage, severe, tameless, thoughtless, tough, tyrannical, unappeasable, unbending, uncalled-for, uncharitable, uncivilized, uncompassionate, uncompassioned, unfeeling, unflinching, unforgiving, ungentle, ungracious, unmerciful, unmoved, unpitiful, unpitying, unrelenting, unremorseful, unsparing, unsympathetic, unsympathizing, untamed, unyielding, vicious, wanton, wild, without mercy