Temperamental (5)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">temperamental</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that temperamental can be written as moody)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for moody that I've seen before include "Irritable" , "Liable to sulking" , "Down in the dumps" , "Temperamental -- capricious" , "Changeable, sullen" .)
(Other definitions for highly strung that I've seen before include "Tense and easily upset" , "Very nervous or volatile" , "Nervous, easily upset" , "Excitable - easily upset" , "like the violino piccolo" .)