Lavish dinner (5)
I believe the answer is:
feast
'lavish dinner' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for feast that I've seen before include "(Eat) a rich meal" , "Belshazzar's party" , "Big meal" , "Junket" , "Tuck-in; blow-out" .)