Almost regretting bankruptcy (4)
I believe the answer is:
ruin
'bankruptcy' is the definition.
(I've seen this before)
'almost regretting' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'regretting' becomes 'ruing' ('rue' can be a synonym of 'regret').
'ruing' with its final letter taken off is 'RUIN'.
(Other definitions for ruin that I've seen before include "Reduce to bankruptcy" , "dishonour" , "State of devastation and destruction" , "Wrecked building" , "Complete collapse or destruction" .)