Scoff during attempt to come to agreement (6)
I believe the answer is:
treaty
'to agreement' is the definition.
(treaty is a kind of agreement)
'scoff during attempt' is the wordplay.
'scoff' becomes 'eat' (I've seen this before).
'during' is an insertion indicator.
'attempt' becomes 'try' (synonyms).
'eat' inserted within 'try' is 'TREATY'.
'to come' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for treaty that I've seen before include "Contract between states" , "alliance" , "convention?" , "Formal agreement between governments" , "Contract, pact" .)