Sudden and striking (8)
I believe the answer is:
dramatic
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">sudden and striking</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for dramatic that I've seen before include "Substantial" , "relating to plays, etc" , "Histrionic" , "Thrilling in effect" , "might be staggering" .)