Corcordat (4)
I believe the answer is:
pact
'corcordat' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for pact that I've seen before include "'Accord, treaty (4)'" , "Agreement, bargain" , "Formal agreement between parties or states" , "Written agreement between two states" , "Alliance" .)