Gnome Alt + F2 clear command history
In a terminal run: dconf-editor In the program that pops up, navigate to: org > gnome > shell In there, find a key called command-history click on it and click the “Set to Default” button. You need to restart the Gnome 3 desktop by log out / log in, or by pressing <Alt>+<F2> and then type in the text field r and press <Enter>

