Certainty (9)
I believe the answer is:
assurance
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">certainty</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that assurance is a type of certainty)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for assurance that I've seen before include "Confidence, certainty" , "(Life) cover" , "Guarantee - belief in oneself" , "what may follow life" , "Cure an ass of a feeling of certainty" .)