a diplomatic official of the highest rank, sent by one sovereign or state to another as its resident representative (ambassador extraordinary and plenipotentiary).

a diplomatic official of the highest rank sent by a government to represent it on a temporary mission, as for negotiating a treaty.

a diplomatic official serving as permanent head of a country's mission to the United Nations or some other international organization.

an authorized messenger or representative. Abbreviation

Amb., amb.

noun

agent , consul , deputy , diplomat , emissary , envoy , minister , plenipotentiary , intermediary , legate , messenger , minister (of thehighest rank)