I’m not sure about debian-based distros, but on Fedora, the default cssh configuration file (~/.csshrc) is configured to use xterm. Personally, I prefer aterm, but simply replacing the ‘terminal’ value (alone) generates an error. You’ve also got to remove the preset ‘terminal_allow_send_events’ values as well, as the preset flags only apply to xterm.
# line(s) 30-31 terminal=/usr/bin/aterm terminal_allow_send_events=
“…and that’s all I’ve got to say about that.”