Striking effect (5)
I believe the answer is:
eclat
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">striking effect</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for eclat that I've seen before include "Distinguished success" , "French renown" , "Ceremonial elegance and splendour" , "Brilliance" , "Brilliant display -- conspicuous success" .)