without remorse; merciless; pitiless; relentless.

adjective

ashamed , guilty , remorseful , sad , sorry

adjective

avaricious , barbarous , bloody , callous , cruel , fierce , forbidding , greedy , grim , hard , hard-bitten , hardened , hard-hearted , harsh , impenitent , implacable , inexorable , inhuman , inhumane , insensitive , intolerant , merciless , murderous , obdurate , pitiless , relentless , rigorous , ruthless , sanguinary , savage , shameless , sour , tough , tyrannical , uncompassionate , uncontrite , unforgiving , unmerciful , unregenerate , unrelenting , unremitting , unrepenting , unyielding , vindictive , adamant , adamantine , brassbound , die-hard , incompliant , inflexible , intransigent , iron , rigid , unbendable , unbending , uncompliant , uncompromising , unrepentant