Water cooler? (3)
I believe the answer is:
ice
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">water cooler</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for ice that I've seen before include "Chill - harden" , "Precious stones" , "Skating surface" , "Diamonds (colloq.)" , "Formality" .)