Unpublishing and Protecting Pages
Unpublishing a page in the Page Settings pop-up window does not mean the page is unavailable, it just means that visitors won’t see it in the menu, but it’s still accessible to anyone who has the link and Google will index the page if there is or ever has been a link to it, so it may still show up in searches.
If you want to disable the page so only Site Editors can get to it there are a couple of options. You can "Protect" the page or you can "rename the alias" to the page.
1) Uncheck the “Publish” box an, and check the “Protected” box in the Page Settings pop up window. Anyone who comes across the link in a Google search will only see a login box on the page, which they can not get passed, but site admin and editors will still be able to see the page when logged in and editing. Also be sure to uncheck the “Sitemap” box, as this is what tells Google to continue indexing the page.
2) Change the “alias” of the page in Page Settings to something new, i.e., if the page alias is currently "ingram-library” for example, change it to "ingram-library-archive” or something that makes sense to you. This disables the link that Google has indexed and visitors will get a “404 Page Not Found” message when trying to access the previous link and eventually Google will remove it from their index altogether.