Test of knowledge (4)
I believe the answer is:
quiz
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">test of knowledge</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 quiz that I've seen before include "Pump" , "Grill" , "Set of questions" , "Q-and-A entertainment" , "Interrogate" .)