| Unmerciful (a.) Not merciful; indisposed to mercy or grace; cruel; inhuman; merciless; unkind. Thesaurus Entries barbarous, bowelless, brutal, brutish, callous, calloused, cold, cold of heart, coldblooded, coldhearted, cruel, dog-eat-dog, flinthearted, flinty, hard, hard of heart, hardened, hardhearted, harsh, heartless, inclement, inexorable, insensitive, mean, merciless, obdurate, pitiless, relentless, remorseless, ruthless, savage, stonyhearted, uncompassionate, uncompassioned, unfeeling, unforgiving, unkind, unnatural, unpitiful, unpitying, unremorseful, unresponsive, unsparing, unsympathetic, unsympathizing, unyielding, vicious, without mercy |