con·cor·dat 
(kən-kôrdăt′)
(kən-kôrdăt′)n.
1. A formal agreement; a compact.
2. An agreement between the pope and a sovereign government concerning the legal status of the Roman Catholic Church within that government's territory.
[French, from Medieval Latin concordātum, from neuter past participle of Latin concordāre, to agree; see CONCORDANT.]