Plenipotentiary

The word plenipotentiary (from the Latin, plenus + potens, full + power) has two meanings. As a noun, it refers to a person who has "full powers." In particular, the term commonly refers to a diplomat fully authorized to represent his or her government as a prerogative (e.g., ambassador). As an adjective, plenipotentiary refers to that which confers "full powers."

Read more about Plenipotentiary:  Diplomats, Administration, Translation