Superior meal has no beginning (5)
I believe the answer is:
upper
'superior' is the definition.
(eg an upper house in a parliament)
'meal has no beginning' is the wordplay.
'meal' becomes 'supper' (supper is a kind of meal).
'has no beginning' means to remove the first letter.
'supper' with its first letter taken away is 'UPPER'.
(Other definitions for upper that I've seen before include "form of stimulant" , "Top of shoe; stimulant" , "The higher of two, berths perhaps" , "Pep pill" , "Part of a shoe; drug" .)