Dogged, unyielding (9)
I believe the answer is:
tenacious
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">dogged</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >'<span class="explanation-format__original">unyielding</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ ></span>
(Other definitions for tenacious that I've seen before include "Holding fast" , "Persevering" , "Holding or sticking firmly" , "Keeping a firm hold" , "Determined" .)