The Alt key is used for many useful commands, but unfortunately it's caught by the terminal window to activate the window menus (File, Edit, ...).
I would like to either force the terminal window to pass Alt to the terminal or get nano to use some other key/combination (I'm using GNOME Terminal 2.32.1).
ps: There is a related, but different question here where it's pointed out that Ctrl + Right Arrow cannot be bound to "move forward a word".
The terminal emulation handles that already. If a key combination with ALT is used by the terminal itself, you can just substitute ALT with ESC. For example, if you want to count characters, words and lines in nano and ALT+D is used by the terminal, just type ESC+D.
For the Alt key to work in the nano editor, run the following command:
It will add the line to the end of your personal xterm config file.
This line makes the setting permanent for future xterm windows. To just change it for the currently open xterm window (and not for other or future windows), you can hold Ctrl while you left-click into the xterm window. While you keep the left mouse button pressed, you select the menu item "Meta Sends Escape".