wm iconwindow window ?pathName?
If pathName is specified, it is the path name for a window to use as icon for window: when window is iconified then pathName will be mapped to serve as icon, and when window is de-iconified then pathName will be unmapped again.
If pathName is specified as an empty string then any existing icon window association for window will be cancelled. If the pathName argument is specified then an empty string is returned. Otherwise the command returns the path name of the current icon window for window, or an empty string if there is no icon window currently specified for window.
Button press events are disabled for window as long as it is an icon window; this is needed in order to allow window managers to "own" those events.
Note: not all window managers support the notion of an icon window.
This command is probably only useful on Unix, and even then not with all window managers.
wm iconwindow may not work immediately. Joe English wrote in comp.lang.tcl: You probably just need to unmap and remap the top-level window, so the window manager will notice the changes:
% wm withdraw . % wm state . normal