You can use the pgrep and pkill commands to identify and stop command processes that you no longer want to run. These commands are useful when you mistakenly start a process that takes a long time to run.

To terminate a process:
a. pgrep – to find out the PID(s) for the process(es)
b. pkill – followed by the PID(s)

The following example illustrates how to find all the processes with a specific name (xterm) and terminate the xterm process that was started last.
# pgrep xterm 17818 17828 17758 18210
# pkill -n 18210

Note: If you need to forcibly terminate a process, use the -9 option to the pkill command.

For Example
# kill -9 -n xterm