Forswear (6)
I believe the answer is:
abjure
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">forswear</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for abjure that I've seen before include "Repudiate - renounce on oath" , "Renounce, forswear" , "(Solemnly) give up" , "Reject" , "Disavow" .)