Delete a list in the List Options menu. Select "Delete" from the drop-down menu.
After you delete a list, you might still be able to restore it.
From the "Lists" pane, click "My lists on top"
. Find "Recently Deleted" in the drop-down menu to see deleted lists. Beside the name of the list you wish to restore, click on "..." and select "Restore".
For video on deleting and restoring lists, see in "Create Additional Lists". (Go to the section for "Create List Duplicate".)