'Valediction' definitions:

Definition of 'valediction'

From: WordNet
noun
A farewell oration (especially one delivered during graduation exercises by an outstanding member of a graduating class) [syn: valediction, valedictory address, valedictory oration, valedictory]
noun
The act of saying farewell

Definition of 'Valediction'

From: GCIDE
  • Valediction \Val`e*dic"tion\, n. [L., valedicere, valedictum, to say farewell; vale farewell (imperative of valere to be strong or well) + dicere to say. See Valiant, Diction.] A farewell; a bidding farewell. --Donne. [1913 Webster] [1913 Webster]