val·e·dic·tion
noun/ˌvælɪˈdɪkʃn/
/ˌvælɪˈdɪkʃn/
[countable, uncountable] (formal)- the act of saying goodbye, especially in a formal speech
（尤指正式演讲中的）告别，告别辞 Word Originmid 17th cent.: based on Latin vale ‘goodbye’ + dicere ‘to say’, on the pattern of benediction.