Well-wisher (11)
I believe the answer is:
sympathiser
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">well-wisher</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that well-wisher can be written as sympathiser)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for sympathiser that I've seen before include "One agreeing with a sentiment or opinion" , "One understanding and agreeing with another's sentiments" .)