Without mercy (8)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">without mercy</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for pitiless that I've seen before include "Without compassion or mercy" , "Harsh, cruel" , "Cold-hearted" , "Callous" , "Remorseless, ruthless" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">without mercy</span>' is the definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for relentless that I've seen before include "Uncompromising" , "sustained" , "Unyielding - implacable" , "Inexorable" , "Allowing no respite" .)