Definition of: plenipotentiary

(plen′i·pə·ten′shē·er′ē, -shə·rē) adjective
Possessing or conferring full powers.
—noun plural ·ar·ies
1. A person fully empowered, especially an ambassador, minister, or envoy, invested with full powers by a government.
2. Specifically, a diplomatic representative of the second class ranking next below an ambassador, accredited by the sovereign or head of one state to that of another: full title envoy extraordinary and minister plenipotentiary. [<L plenus full + potens powerful]