UPDATE- the Joomla team added this functionality to the core, and with a current release version it is easy to hide menu items. Simply look for the 'Link Type' tab when editing the menu item, and set the 'Display in Menu' option to no. This will hide your menu item in the menu. If you are still using an older version of Joomla you'll need to keep reading below, but you should upgrade your Joomla install.
Do you need to add pages to your Joomla website that don't appear on the public navigation? We wrote a post about this recently, and described the process to add these to a hidden menu.
A hidden menu is a menu that does not appear on the public navigation on your website. The process for adding a hidden menu in the Joomla admin is:
That's it! In just 3 steps you have a place to add menu items for hidden pages, like landing pages, thank you pages, or any other page that you don't want on your main navigation menus.
You can use any title and menu type name that you like. In this example, we'll name the menu "Hidden Menu". You could also call this Nonpublic menu, Landing Page menu, or other descriptive names. And you can have multiple hidden menus if you like, which can be helpful in managing a more complex site.
When you add a new menu, Joomla no longer adds a new module by default as it did in previous versions. This is the key to why visitors won't see your menu. With no published module for the menu, it simply won't display anywhere on your website.
Look at what a difference a website redesign makes!