Unpleasantly moist (4)
I believe the answer is:
dank
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">unpleasantly moist</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 dank that I've seen before include "(Of atmosphere) wet and unpleasant" , "Chilly and clammy" , "Unpleasantly cool and damp" , "Unpleasantly cold and humid" , "Cold and moist" .)