Any fizzy drink (4)
I believe the answer is:
soda
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">any fizzy drink</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 soda that I've seen before include "Fizzy drink - chemical compound" , ""Splashed" drinks mixer" , "for use with whisky?" , "Splash served with some spirits" , "Alkaline substance used in cleaning, drinks etc" .)