Trashed pages remain available to Restore for 30 days, then they’re gone.
Select Quick Edit to set the Page to a Draft. A Draft removes the page from the public front end but you’ll still see it since you’re logged in. This can be confusing so just note.
Re-enable the page or post by setting it back to Published.
If you want to reuse the URL of a trashed page for a new page you’ll need to “Delete Permanently” the page.
You’ll find this option by checking the Trash link at the very top of the Page or Post listings (small link).
Important: Delete links to the page you removed. You’ll need to remove links to the page from other pages or the main navigation. Instructions on left.