plenipotentiary \plen-uh-puh-TEN-shee-air-ee; -shuh-ree\, adjective:1. Containing or conferring full power; invested with full power; as, "plenipotentiary license; plenipotentiary ministers." noun:1. A person invested with full power to transact any business; especially, an ambassador or diplomatic agent with full power to negotiate a treaty or to transact other business.What a great word to start 2011. Happy New Year!