plenipotentiary

/ˌˈplɛnəpəˌtɛntʃəri/

Other forms: plenipotentiaries

An ambassador who independently represents their home country in another country can be called a plenipotentiary.

The word plenipotentiary comes from Latin roots, plenus, "complete or full," and potentem, "powerful." Someone who is a plenipotentiary literally has full powers to represent their government — the prime minister or president has officially authorized them to sign treaties or other agreements on behalf of that government. Some (but not all) diplomats are plenipotentiaries.

Definitions of plenipotentiary

1. noun

   a diplomat who is fully authorized to represent his or her government
   type of:

   diplomat, diplomatist

   an official engaged in international negotiations
2. adjective

   having full or complete power