the last act or manifestation of someone or something; farewell appearance:
This building turned out to be the swan song of Victorian architecture.
Origin
1825-35; so called from the belief that the dying swan sings
Examples from the web for swan song
It was the swan song of my pension and the developed nations.
The missing element may be unimaginably powerful reverberations-the sound of a star singing its own swan song.
Now astronomers think of them as the ultimate stellar swan song.
The swan song of the sailing ship has been sung these many years.
British Dictionary definitions for swan song
swan song
noun
1.
the last act, appearance, publication, or utterance of a person before retirement or death
2.
the song that a dying swan is said to sing
Idioms and Phrases with swan song
swan song
A final accomplishment or performance, one's last work. For example, I'm resigning tomorrow; this project was my swan song. This term alludes to the old belief that swans normally are mute but burst into beautiful song moments before they die. Although the idea is much older, the term was first recorded in English only in 1890.