I'd return to break agreement in dispute (10)
I believe the answer is:
contradict
'dispute' is the definition.
(I've seen this before)
'i'd return to break agreement' is the wordplay.
'return' is a reversal indicator.
'to break' indicates putting letters inside (inserted letters break into the word).
'agreement' becomes 'contract' (contract is a kind of agreement).
'id' backwards is 'di'.
'di' going into 'contract' is 'CONTRADICT'.
'in' is the link.
(Other definitions for contradict that I've seen before include "Have a different view" , "Argue against" , "dispute" , "Deny" , "Be in conflict with" .)