Inexorable (7)
I believe the answer is:
adamant
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">inexorable</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for adamant that I've seen before include "Resolute; diamond (arch.)" , "intractable" , "Firmly unchanging" , "uncompromising" , "Unshakable (in an opinion)" .)