Some sub-menus in the Enterprise Architect main menu are tear off menus. This is indicated by the bar at the top. For example, the Element | Make Same sub-menu is a tear off menu:
A tear off menu can be dragged out of the menu structure into its own window. Simply click on the bar at the top and drag it away. The menu detaches itself as shown here:
Once detached, the menu can also be docked in the toolbar section at the top of the screen, or on the edges of the workspace.