Disincentive (9)
I believe the answer is:
deterrent
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">disincentive</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 deterrent that I've seen before include "Something intended to discourage" , "It acts to discourage" , "Nuclear weapons allegedly" , "Something that puts people off" , "Eg, a nuclear weapon" .)