Strongly alcoholic (4)
I believe the answer is:
hard
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">strongly alcoholic</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 hard that I've seen before include "Difficult - firm" , "Difficult; rigid" , "Complicated" , "impenetrable" , "Solid; tough" .)