valediction
/ˌvælɪˈdɪkʃən/noun
mass noun
1- the action of saying farewell告别：
he spread his palm in valediction.
他伸开手掌告别。
1.1
- count noun a statement or address made at or as a farewell告别词：
his official memorial valediction.
他的正式纪念告别词。
词源
mid 17th cent.: based on Latin vale 'goodbye' + dicere 'to say', on the pattern of benediction.