valediction

noun

1. （尤指正式演讲中的）告别，告别辞
   the act of saying goodbye, especially in a formal speech

1. He gave a touching valediction at graduation.
   他在毕业典礼上发表了动人的告别辞。

noun

1. the act of saying farewell

2. a farewell oration (especially one delivered during graduation exercises by an outstanding member of a graduating class)

   Synonym:    valedictory addressvaledictory orationvaledictory