Weaken finally in bankruptcy dispute (3,2)
I believe the answer is:
run-in
'dispute' is the definition.
(run-in is a kind of dispute)
'weaken finally in bankruptcy' is the subsidiary indication.
'finally' says to take the final letters.
'in' means one lot of letters goes inside another.
'bankruptcy' becomes 'ruin' (I've seen this before).
The final letter of 'weaken' is 'n'.
'n' inserted into 'ruin' is 'runin'.
(Other definitions for run-in that I've seen before include "Home straight" , "Matches late in season" , "Disagreement (with authority?)" , "Quarrel" , "Dispute" .)