Sometimes your content goals require specific pages to remain hidden from the masses, and if it is easy to exclude a page/post from being indexed by search engines (setting it to noindex in your SEO plugin options), hiding a page from your native site search results is a little trickier.
There isn’t a ready solution for that in WordPress (yet).
But thanks to the good guys out there, who develop free WordPress plugins, there is a simple way for hiding specific pages from being found through site search.
No need for adding code to your functions.php file or some other complicated tasks.
Here it comes…
Search Exclude Plugin

You can tell by the name that this plugin is doing what it’s meant to do.
You’ll see the checkbox on your page/post settings panel (this also works with Gutenberg editor).

Simple and working as it should!