Treated badly (7)
I believe the answer is:
misused
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">treated badly</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 misused that I've seen before include "polluted, perhaps?" , "wasted?" , "Treated badly" , "Applied wrongly" , "Did exploit" .)