Not much for mixing (7)
I believe the answer is:
asocial
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">not much for mixing</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 asocial that I've seen before include "without friends" , "Solitary" , "Not fond of company, perhaps inconsiderate" , "lacking friendly instincts" , "Not gregarious" .)