Silliness (7)
I believe the answer is:
inanity
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">silliness</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 inanity that I've seen before include "act of stupidity" , "Mindlessness" , "Silliness in a tiny way" , "Foolishness" , "Being silly" .)