Kind of metal – party (6)
I believe the answer is:
thrash
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">kind of metal</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(thrash metal is a genre of music)</span><br/ ><br/ >'<span class="explanation-format__original">party</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(thrash can informally mean a party)</span><br/ ><br/ ></span>
(Other definitions for thrash that I've seen before include "Wallop" , "Lay on - party" , "Beat heavily, perhaps with whip" , "Best" , "Beat with stick or whip" .)