/ ˌplenɪpəˈtenʃəri; NAmE ; NAmE also -ʃieri/ noun
( pl. -ies ) ( technical ) a person who has full powers to take action, make decisions, etc. on behalf of their government, especially in a foreign country
► pleni·po·ten·tiary adjective :
plenipotentiary powers
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WORD ORIGIN
mid 17th cent.: from medieval Latin plenipotentiarius , from plenus full + potentia power.