1) Bloody 2) Bowelless 3) Cruel 4) Cutthroat 5) Fierce 6) Hard 7) Having or showing no mercy 8) Implacable 9) Inclement 10) Merciless 11) Mortal 12) Pitiless 13) Relentless 14) Remorseless 15) Ruthless 16) Severe 17) Tigerish 18) Uncompassionate 19) Unkind 20) Unpitying 1) Bloody 2) Bowelless 3) Cutthroat 4) Flinty 5) Implacable 6) Merciless 7) Pitiless 8) Remorseless 9) Ruthless 10) Tigerish 11) Uncompassionate 12) Unkind 13) Unmercied 14) Unpitying 15) Unsparing 
• (a.) Not merciful; indisposed to mercy or grace; cruel; inhuman; merciless; unkind.
merciless; relentless; severe; cruel; pitiless. · unsparingly great, extreme, or excessive, as amounts: to talk for an unmerciful length of time.