To disable any parent item in WordPress Menu

Following are instructions on how to disable a parent menu item from the WordPress menu without the use of plugins or code changes.

1. In the dashboard go to Appearances/Menus
2. Go to Screen Options (top right) and activate Link Target by checking box.
3. Go to Custom Links and insert any kind of link, and then Label it what you want your menu item to be called.
4. Add to menu
5. Select the just created custom link. click on the dropdown link on the top right side of its box.
6. Delete the URL from the link target field and to ensure that the no-link parent menu item will show on mobile devices replace with #
7. Add submenu items.
8. Done!