I'd turn up to break agreement in dispute (10)
I believe the answer is:
contradict
'dispute' is the definition.
(thesaurus)
'i'd turn up to break agreement' is the wordplay.
'turn up' says the letters should be written backwards.
'to break' indicates putting letters inside.
'agreement' becomes 'contract' (contract is a kind of agreement**).
'id' back-to-front is 'di'.
'di' put within 'contract' is 'CONTRADICT'.
'in' acts as a link.
(Other definitions for contradict that I've seen before include "dispute" , "Argue against" , "Deny" , "Have a different view" , "Gainsay" .)