Budgetary excess (3)
I believe the answer is:
fat
'budgetary excess' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for fat that I've seen before include "Cooking grease" , "Obese, having spare tyre etc" , "Substantial" , "Adipose tissue" , "Obese, overweight" .)