Tainted (6)
I believe the answer is:
impure
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tainted</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 impure that I've seen before include "Assign a value to" , "Sullied or adulterated" , "Adulterated or unchaste" , "Tainted, not chaste" , "Contaminated or licentious" .)