Rankle (6)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">rankle</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for fester that I've seen before include "Rankle" , "Putrefy" , "Rot" , "Of wound, form yellow pus" , "Go septic or cause resentment" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">rankle</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>