Wait on minister after a time (6)
I believe the answer is:
attend
'wait on' is the definition.
'minister after a time' is the wordplay.
'minister' becomes 'tend' (I've seen this before).
'after' is a charade indicator (letters next to each other).
'time' becomes 't'.
'a'+'t'='at'
'tend' after 'at' is 'ATTEND'.
(Other definitions for attend that I've seen before include "Follow" , "Be present or appear at" , "Watch" , "Being 16 [LISTEN]" , "Concentrate carefully" .)