Mixer with gin (5)
I believe the answer is:
tonic
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">mixer with gin</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for tonic that I've seen before include "Invigorating drink" , "Key" , "Stimulant" , "Invigorating liquid" , "medicinal preparation" .)