Desire to drink (6)
I believe the answer is:
thirst
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">desire to drink</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 thirst that I've seen before include "Drink to slake it" , "A need (for liquid)" , "Strong desire for something" , "drought" , "T-shirt (anag)" .)