Charity event held inside cafeteria (4)
I believe the answer is:
fete
'charity event' is the definition.
(I've seen this before)
'held inside cafeteria' is the wordplay.
'held' indicates the answer is hidden within the clue.
'FETE' can be found hidden inside 'inside cafeteria'.
(Other definitions for fete that I've seen before include "Festival event" , "Outdoor gala" , "Honour lavishly; outdoor function" , "Marilyn Monroe's real first name' constellation" , "Outdoor entertainment run for charity" .)