Event attended by Cinderella (4)
I believe the answer is:
ball
'event attended by cinderella' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ball that I've seen before include "Spherical plaything" , "Social function for dancing" , "20" , "Formal social event" , "Old song: 'After the .... was over'" .)