From Longman Dictionary of Contemporary Englishvaledictionval‧e‧dic‧tion /ˌvæləˈdɪkʃən/ noun [countable, uncountable] formal GOODBYEthe act of saying goodbye, especially in a formal speech → farewell
Examples from the Corpus
valediction• 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. 