Spectacular (12)
I believe the answer is:
extravaganza
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">spectacular</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 extravaganza that I've seen before include "Lavish display" , "Elaborately staged show" , "Big performance" , "Lavishly staged entertainment" , "Elaborately staged light entertainment" .)