noun
plenipotentiary
A diplomatic representative with full authority to act on behalf of a government or organization, often in treaty negotiations.
日本は平和条約の交渉に全権委員を派遣した。
Japan dispatched a plenipotentiary to the peace treaty negotiations.
全権 means 'full authority' or 'plenipotentiary power' and is often used as a prefix or in compounds like 全権大使 (ambassador plenipotentiary). 全権委員 specifically refers to a committee member or delegate with such authority.
大使 is a general term for 'ambassador', while 全権委員 is a more specific term for a plenipotentiary representative, often with a narrower or temporary mandate.
Compound of 全権 (full authority) + 委員 (committee member). The term is a direct translation of the Western diplomatic concept of 'plenipotentiary'.