Took (an exam) again (5)
I believe the answer is:
resat
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">took an exam again</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for resat that I've seen before include "was tested again" , "did test again" , "Took (exam) again" , "went back to the paper" , "Took another chance to pass" .)