Explosion or eruption (8)
I believe the answer is:
outburst
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">explosion</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I have seen 'Explosion of emotion' mean 'outburst' so perhaps 'explosion' could also mean 'outburst')</span><br/ ><br/ >'<span class="explanation-format__original">eruption</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for outburst that I've seen before include "Angry words" , "Eruption of violent emotions" , "Effusion of violent emotion" , "Sudden disturbance" , "Unrestrained expression of strong emotion" .)