Remove search results
As a global or SharePoint admin in Office 365, you can temporarily remove items from search results with immediate effect. The items that you can remove can be documents, pages, or sites that you don't want users to see. An example of this could be a Word document containing an invitation to an event that has been cancelled, but the organizer has not removed the document from the site yet. Removing a result removes it from both classic and modern search results.
This is only a quick fix! Unless you delete the items or change the permissions of items manually, they will show up again in your search results after the next crawl.
Sign in to https://admin.microsoft.com as a global or SharePoint admin. (If you see a message that you don't have permission to access the page, you don't have Office 365 administrator permissions in your organization.)
In the left pane, under Admin centers, select SharePoint. (You might need to select Show all to see the list of admin centers.)
If the classic SharePoint admin center appears, select Open it now at the top of the page to open the new SharePoint admin center.
Select Classic features.
Under Search, select Open.
On the search administration page, choose Remove Search Results.
On the Remove Search Results page, in the URLs to remove box, type the URLs that you want to remove from the search results. Type one URL on each line.
Select Remove Now. The URLs are immediately removed from your search results.