Perfectly clean (8)
I believe the answer is:
spotless
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">perfectly clean</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 spotless that I've seen before include "honest!" , "Extremely clean" , "How Lady Macbeth wanted to be" , "Immaculately clean" , "Perfect" .)