From Longman Dictionary of Contemporary Englishplenipotentiaryplen‧i‧po‧ten‧tia‧ry /ˌplenəpəˈtenʃəri $ -ʃieri/ noun (plural plenipotentiaries) [countable] formal or technical PGOsomeone who has full power to take action or make decisions, especially as a representative of their government in a foreign country —plenipotentiary adjective
Examples from the Corpus
plenipotentiary• Are they delegates, representatives or plenipotentiaries, for instance?• At both guberniia and central levels the Soviet government established a liaison system between their own plenipotentiaries and all foreign relief organizations.• And what have the Portland Place plenipotentiaries to say about it?• There were plenipotentiaries in court uniforms so decked with gold that their coats seemed like sheets of light.Origin plenipotentiary (1600-1700) Medieval Latin plenipotentiarius, from Latin plenus ( → PLENTY3) + potens “powerful” 