noun / adjective

plenipotentiary

plen-ih-puh-TEN-shee-air-ee/ˌplenɪpəˈtenʃieri/

Having or exercising full authority to act on behalf of a government.

The plenipotentiary envoy has full authority to negotiate the treaty.

Ambassador signs treaty bearing large official seal while counterpart accepts it, sealed letter of full authority beside her; only simple seal/lines without words, small negotiation table.

Etymology

pleniLatinfull, complete

+potentLatinto be able, be powerful

+iaryLatinrelating to

Fullness and power combine in the idea of someone invested with full powers. The adjective became a noun for an authorized representative, especially an ambassador empowered to negotiate treaties or conduct government business.

More examples

Each government sends a plenipotentiary to the peace talks.
The two plenipotentiaries sign the agreement for their governments.
She serves as ambassador extraordinary and plenipotentiary.

Forms

plenipotentiary · plenipotentiaries

Similar words

diplomat: A broader term for an official conducting international relations.
envoy: An appointed representative whose authority may be limited.