Superior and wise custom? (5)
I believe the answer is:
usage
'custom?' is the definition.
(synonyms)
'superior and wise' is the wordplay.
'superior' becomes 'u' (I've seen this in other clues).
'and' means one lot of letters go next to another.
'wise' becomes 'sage' (similar in meaning).
'u'+'sage'='USAGE'
(Other definitions for usage that I've seen before include "Interest of old" , "Habitual custom" , "management" , "Utilisation" , "Habit" .)