plenipotential
/ˌplɛnɪpəˈtɛnʃl/adjective
Of or belonging to a plenipotentiary; possessing or conferring full power or authority.
Origin
Mid 17th century; earliest use found in Guy Miege (bap. 1644, d.?1718), author and lexicographer. From post-classical Latin plenipotent-, plenipotens plenipotent + -ial, probably after potential. Slightly earlier currency is probably implied by plenipotentiality.