Show dissatisfaction (3)
I believe the answer is:
boo
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">show dissatisfaction</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for boo that I've seen before include "Poor reception" , "Frightening word (for a goose?)" , "I hated that!" , "Expression of disapproval" , "Sound expressing disapproval" .)