Sharp-tasting, sour (6)
I believe the answer is:
acidic
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">sharp</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">tasting sour</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for acidic that I've seen before include "Tasting sharp or sour" , "Vinegary" , "Sour; bitter" , "Sharp-tasting, sour" , "Sarcastic or sour" .)