Celebration, carnival (6)
I believe the answer is:
fiesta
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">celebration</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(fiesta is a kind of celebration)</span><br/ ><br/ >'<span class="explanation-format__original">carnival</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for fiesta that I've seen before include "Feast day" , "Continental knees-up" , "Religious event" , "(Spanish) religious festival" , "Religious festival in Spain" .)