Deleting a site
How do I exclude a site or some pages from the search?
Remove the pages from your site (so that the server returns the
404 Not found HTTP status code when the URL is requested) or prohibit their indexing in robots.txt. Then use the Delete URLDelete URL form.
Next time the robot crawls your site, the pages you deleted or prohibited from indexing will be excluded from the search results.
We recommend viewing How to remove a page from the search.