Habit of minister when talking something over (7)
I believe the answer is:
surplus
'over' is the definition.
(thesaurus)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for surplus that I've seen before include "(An) oversupply" , "a bit over the top" , "Redundant" , "Remainder" , "superfluity" .)