Carbonated drink (4)
I believe the answer is:
soda
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">carbonated 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 soda that I've seen before include "for use with whisky?" , "In the US, a sweet fizzy drink" , "Fizzy drink - chemical compound" , "Alkaline substance used in cleaning, drinks etc" , "Accompaniment to whisky" .)