Where does the title 'Slaughterhouse Five' come from? 'Slaughterhouse Five' is also known under another title. What is it?

Slaughterhouse-Five actually has a few different meanings in terms of the novel. It is the name of the prison in which Billy and the other POWs are kept (the prison is a slaughterhouse). It is also a metaphor for the way in which Vonnegut sees war..... as slaughter. Lastly, it reflects Vonnegut's own experiences after WWII, the time he spent as a prisoner of war.

The other title you've asked about is The Children's Crusade: A Duty-Dance with Death.