slay finds and kills all the user's processes at once, saving you the trouble of hunting them down and killing them yourself. slay has four modes: nice, normal, mean, and butthead. Mean mode kills any nonprivileged user who attempts to slay another user. Set your desired mode in slay shell script.
Open terminal from Applications > Accessories > Terminal, and type following command to install
sudo apt-get install slayUsing Slay:
Open up the terminal and type following command to kill the entire session of user 'test'
slay testAnother way to kill all the process belong to user 'test' is by using command: killall -u test