Break off very bad contracts (5)
I believe the answer is:
sever
'break off' is the definition.
(I've seen this in another clue)
'very bad contracts' is the wordplay.
'very bad' becomes 'severe' (I've seen this before).
'contracts' means to remove the last letter (I've seen 'contracted' mean this (to contract is to shorten)).
'severe' with its last letter removed is 'SEVER'.
(Other definitions for sever that I've seen before include "Cut right off" , "Divide by cutting" , "Cut apart, maybe a relationship" , "Cut completely" , "Divorce" .)