Moody (13)
I believe the answer is:
temperamental
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">moody</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for temperamental that I've seen before include "Liable to changes of mood" , "Having a volatile disposition" , "Unreliable" , "Capricious" , "Likely to act unpredictably" .)