Individual elements ( and their children ) can be excluded using the Search index settings feature at the bottom of the element's settings panel.
Individual pages can be excluded using the Site Search Settings feature on the page's settings. Collection page templates can be excluded the same way- however this applies to the page as a whole.
Individual collection item pages, and individual collection items ( in a collection list ) cannot be suppressed individually.
[ Confirmed by Webflow support 12-Jul-2023 ]
IMPORTANT: None of these settings will affect indexing by public search engines such as Google.
Webflow Site search
https://university.webflow.com/lesson/site-search#indexing-and-controlling-what-is-%E2%80%9Csearchable%E2%80%9D
Democratizing search technology — by bringing it to Webflow
https://webflow.com/blog/democratizing-search-technology-by-bringing-it-to-webflow
