Merriam-Webster's Word of the Day for June 1, 2017 is:

valedictory • \val-uh-DIK-tuh-ree\  • adjective

: of or relating to an act of bidding farewell : expressing or containing a farewell

Examples:

"During one of two valedictory addresses, Fredrick challenged her classmates to make a difference after graduation and took the time to thank all teachers." — Nathan Thompson, The Bartlesville (Oklahoma) Examiner-Enterprise, 14 May 2017

"When Julian Wachner arrived in Washington to head the Washington Chorus, he was seething with unfocused energy: a man with a lot to prove. On Sunday, nearly 10 years later, he led his valedictory performance as the chorus's music director." — Anne Midgette, The Washington Post, 16 May 2017

Did you know?

Valedictory addresses delivered by earnest young valedictorians at high school and college graduations are as much a sign of spring in the United States as baseball games and cookouts. Though we don’t know where the first valedictory address was given, we do know that the word was an institution at some colleges in the U.S. by the mid-1700s. English speakers and writers have also used valedictory in non-academic settings since the mid-1600s. Since a valedictory speech is given at the end of an academic career, it is perfectly in keeping with the meaning of its Latin ancestor, valedicere, which means "to say farewell."