Be prompt after pub meal (8)
I believe the answer is:
barbecue
'meal' is the definition.
(barbecue is a kind of meal)
'be prompt after pub' is the wordplay.
'prompt' becomes 'cue' ('cue' can be a synonym of 'prompt').
'after' is a charade indicator (letters next to each other).
'pub' becomes 'bar' (I've seen this before).
'be'+'cue'='becue'
'becue' after 'bar' is 'BARBECUE'.
(Other definitions for barbecue that I've seen before include "Cuba beer (anag.)" , "Cuba beer for outdoor meat meal" , "Outdoor eating occasion" , "Alfresco meal" , "Portable grill for cooking outdoors" .)