valediction
From Longman Dictionary of Contemporary Englishvaledictionval‧e‧dic‧tion /ˌvæləˈdɪkʃən/ noun [countable, uncountable] formal GOODBYEthe act of saying goodbye, especially in a formal speech → farewellExamples from the Corpusvalediction• It sounded more like a courtesy than a threat, a valediction.• Yet there was not even a hint of valediction in last week's speech on Capitol Hill.• Agassi's victory speech had more than a touch of valediction.