Stimulant provided after beginning of meal? (5)
I believe the answer is:
upper
'stimulant' is the definition.
(thesaurus)
'after beginning of meal?' is the wordplay.
'after beginning of' means to remove the first letter (ignoring the first letter).
'meal?' becomes 'supper' (supper is a kind of meal).
'supper' with its initial letter taken away is 'UPPER'.
'provided' acts as a link.
(Other definitions for upper that I've seen before include "that's found in shoe" , "Higher; superior" , "Stimulant drug (informal)" , "Part of shoe above sole" , "Higher in position; drug" .)