Display a cursor to select a window to kill by pressing any mouse button

Kill a window interactively in a graphical session.
See also `kill` and `killall`.
More information: <https://www.x.org/releases/current/doc/man/man1/xkill.1.xhtml>.
Trick copyright: tl;dr; <https://github.com/tldr-pages/tldr>

xkill -button any

click the source code to copy install xkill on any operating system with command-not-found.com