Completely remove pr exclude pages from the front-end

I have a very customized website that uses a system I have develop that allows users to create landing pages by combining multiple child pages into one. Each landing page has a parent and a number of child pages for each section.

Is there a way for me to disable/remove/hide this child pages from being displayed and served to users and search engines? They need to be editable in the admin but should not be visible on the site.

Thanks!