Important topic for debate (5)
I believe the answer is:
issue
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">important topic for debate</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 issue that I've seen before include "Important topic for debate" , "Matter, point" , "important subject" , "Result, outcome; topic" , "litter" .)