Ascertained (7)
I believe the answer is:
ensured
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">ascertained</span>' is the definition.<br/ ><span class="explanation-format__explanation">('ensure' can be a synonym of 'ascertain')</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for ensured that I've seen before include "Determined" , "Make certain of" , "guaranteed" , "Made certain for end user" , "Made certain, clinched" .)