Dogged (9)
I believe the answer is:
tenacious
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">dogged</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for tenacious that I've seen before include "Persistent in holding on" , "Dogged" , "Holding or sticking firmly" , "Holding fast" , "Determined" .)