Edit Order Status
In the old admin, you could edit the order status names or determine which are visible, by clicking the “Edit Order Status” link in the Settings ->General ->Store Settings page.
In the updated Admin, the “Edit Order Status” is now located by going to Settings ->General ->Store Settings, and clicking on the “Checkout” tab found along the top. Within the Checkout section of that page, you will see a link labeled “Edit Order Status”
By clicking this link, you’ll be taken to the page where you will be able to rename and/or hide individual statuses.