State positively (4)
I believe the answer is:
aver
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">state positively</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 aver that I've seen before include "'Affirm, assert (4)'" , "say, with conviction" , "Profess" , "State (to be the case)" , "Declare or insist" .)