val ‧ e ‧ dic ‧ to ‧ ry /ˌvæləˈdɪkt ə ri◂/ BrE AmE noun ( plural valedictories ) [countable] formal
[ Date: 1600-1700 ; Language: Latin ; Origin: valedictus , past participle of valedicere 'to say goodbye' , from vale 'goodbye' + dicere 'to say' ]
a speech or statement in which you say goodbye when you are leaving a school, job etc, especially on a formal occasion
—valedictory adjective :
a valedictory speech