Definition of fetial:
(n) :
(Ancient Rome, politics, religion, historical) A member of the Roman college of priests who acted as representatives in disputes with foreign nations.
(adj) :
Of or relating to a fetial (member of the Roman college of priests who acted as representatives in disputes with foreign nations); (by extension) ambassadorial, heraldic.
(adj) :
Concerned with declarations of war and treaties of peace.