Confident statement of fact (9)
I believe the answer is:
assertion
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">confident statement of fact</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for assertion that I've seen before include "Claim" , "Notarises (anag)" , "Confident statement of fact" , "Confident declaration" , "Emphatic declaration" .)