This works..
xdotool search "Mozilla Firefox" windowminimize
but this does not minimize my Terminal.
xdotool search "Terminal" windowminimize
Defaulting to search window name, class, and classname
wmctrl -l
0x01400003 -1 andy-To-be-filled-by-O-E-M Top Panel
0x01400017 -1 andy-To-be-filled-by-O-E-M Bottom Panel
0x01400025 -1 andy-To-be-filled-by-O-E-M Top Panel
0x01600006 -1 andy-To-be-filled-by-O-E-M Desktop
0x02800007 0 andy-To-be-filled-by-O-E-M Downloads - Thunar
0x0360003e 0 andy-To-be-filled-by-O-E-M How to minimize an application window from command line - Unix & Linux Stack Exchange — Mozilla Firefox
0x03800006 0 andy-To-be-filled-by-O-E-M Terminal
0x03c00007 0 andy-To-be-filled-by-O-E-M *untitled - Geany
Why isn't my Terminal being minimized?