plenipotentiary
C2Գոյական/US /ˌplɛnɪpəˈtɛnʃjɚɹi/ ˌplĕnĭpəˈtĕnshyərrē; UK /ˌplɛnɪpəˈtɛnʃjəɹi/ ˌplĕnĭpəˈtĕnshyərē/
A person invested with full power to transact any business; especially, an ambassador or envoy to a foreign court, with full power to negotiate a treaty, or to transact other business.