Scoff in attempt to get agreement (6)
I believe the answer is:
treaty
'agreement' is the definition.
(treaty is a kind of agreement)
'scoff in attempt' is the wordplay.
'scoff' becomes 'eat' (I've seen this before).
'in' means one lot of letters goes inside another.
'attempt' becomes 'try' (I've seen this before).
'eat' going within 'try' is 'TREATY'.
'to get' acts as a link.
(Other definitions for treaty that I've seen before include "International agreement" , "Compact - agreement" , "convention?" , "Contract between states" , "Covenant" .)