swan song SWAHN-SONG, noun:
1. A beautiful legendary song said to be sung by a dying swan.
2. A final or farewell appearance, action, or pronouncement.

As one of the playwright’s biographers put it, Schnitzler
sang “the swan song of old Vienna” and “caught in his
gentle hand the last golden glow of its setting glory and
converted it into art.”
–Arthur Lennig, Stroheim

Opposition leaders dismissed the Chancellor’s speech as the
swan song of a leader who has, after 16 years in office,
overstayed his welcome with the electorate.
–“Kohl predicts victory despite polls,” [1]Irish Times,
May 19, 1998