Big test; torture (6)
I believe the answer is:
ordeal
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">big test</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >'<span class="explanation-format__original">torture</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that ordeal is a type of torture)</span><br/ ><br/ ></span>
(Other definitions for ordeal that I've seen before include "A difficult and harrowing experience" , "Difficult experience that tests endurance" , "Difficult experience, a tough time" , "Disturbing experience" , "Severe or trying experience" .)