Excellency
noun uk/ˈek.səl.ən.si/ us/ˈek.səl.ən.si/
Your Excellency/His Excellency （尤指对大使等的尊称）阁下
the title of someone in an important official position, especially someone, such as an ambassador, who represents their government in a foreign country
His Excellency will be pleased to see you now. 大使阁下现在会很高兴见到您的。