Budgetary control initially fails disastrously (6)
I believe the answer is:
fiscal
'budgetary' is the definition.
(I've seen this before)
'control initially fails disastrously' is the wordplay.
'initially' says to take the initial letters.
'disastrously' indicates an anagram (I've seen this in other clues).
The initial letter of 'control' is 'c'.
'c'+'fails'='cfails'
'cfails' with letters rearranged gives 'FISCAL'.
(Other definitions for fiscal that I've seen before include "To do with public revenue of califs" , "In respect of tax revenues" , "Califs (anag.)" , "Relating to government finances" , "regarding tax" .)