Make moist (6)
I believe the answer is:
dampen
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">make 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 dampen that I've seen before include "Make moist or depress spirit" , "Moisten" , "Apply liquid!" , "Make slightly moist, or discourage" , "Stifle" .)