Debauched man saves money for habit (7)
I believe the answer is:
routine
'habit' is the definition.
(I've seen this before)
'debauched man saves money' is the wordplay.
'debauched man' becomes 'roue' (I've seen this before).
'saves' means one lot of letters goes inside another.
'money' becomes 'tin' (I've seen this before).
'roue' placed around 'tin' is 'ROUTINE'.
'for' is the link.
(Other definitions for routine that I've seen before include "Schedule, standard procedure" , "Regularly performed" , "Normal procedure" , "Regular programme" , "Normal practice" .)