Disgustingly dirty (6)
I believe the answer is:
filthy
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">disgustingly dirty</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 filthy that I've seen before include "Nasty - smutty" , "Extremely dirty" , "Dirty - smutty" , "rude?" , "Really dirty, disgusting" .)